Tcl Source Code

2007-10-26  Don Porter	<[email protected]>

	*** 8.5b2 TAGGED FOR RELEASE ***

	* changes:		Updated for 8.5b2 release.





	* README:		Bump version number to 8.5b2.
	* generic/tcl.h:
	* library/init.tcl:
	* tools/tcl.wse.in:
	* unix/configure.in:
	* unix/tcl.spec:

Recent user-visible changes to Tcl:

RCS: @(#) $Id: changes,v 1.120 2007/10/26 15:53:43 dgp Exp $

1. No more [command1] [command2] construct for grouping multiple
commands on a single command line.

2. Semi-colon now available for grouping commands on a line.

3. For a command to span multiple lines, must now use backslash-return

2007-10-11 (bug fix)[1805887] [string is int -failindex] for 0o, 0b (porter)

2007-10-15 (bug fix)[1813528] Tcl_ParseBraces read past buffer (mistachkin)

2007-10-25 (bug fix)[1726873] intermittent crash in threads (vasiljevic)

New doc macros for improved formatting.  Docs updated to use. (fellows)

--- Released 8.5b2, October 26, 2007 --- See ChangeLog for details ---

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: AppInit.3,v 1.6 2007/10/24 14:29:37 dkf Exp $
'\" 
.so man.macros
.TH Tcl_AppInit 3 7.0 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_AppInit \- perform application-specific initialization
.SH SYNOPSIS
.nf
\fB#include <tcl.h>\fR
.sp
int
\fBTcl_AppInit\fR(\fIinterp\fR)
.SH ARGUMENTS
.AS Tcl_Interp *interp
.AP Tcl_Interp *interp in
Interpreter for the application.
.BE

.SH DESCRIPTION
.PP
\fBTcl_AppInit\fR is a
.QW hook
procedure that is invoked by
the main programs for Tcl applications such as \fBtclsh\fR and \fBwish\fR.
Its purpose is to allow new Tcl applications to be created without
modifying the main programs provided as part of Tcl and Tk.
To create a new application you write a new version of
\fBTcl_AppInit\fR to replace the default version provided by Tcl,
then link your new \fBTcl_AppInit\fR with the Tcl library.
.PP

'\"
'\" Copyright (c) 1992-1994 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: BackgdErr.3,v 1.5 2007/10/24 14:29:37 dkf Exp $
'\" 
.so man.macros
.TH Tcl_BackgroundError 3 7.5 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_BackgroundError \- report Tcl error that occurred in background processing
.SH SYNOPSIS
.nf
\fB#include <tcl.h>\fR
.sp
\fBTcl_BackgroundError\fR(\fIinterp\fR)
.SH ARGUMENTS
.AS Tcl_Interp *interp
.AP Tcl_Interp *interp in
Interpreter in which the error occurred.
.BE

.SH DESCRIPTION
.PP
This procedure is typically invoked when a Tcl error occurs during
.QW "background processing"
such as executing an event handler.
When such an error occurs, the error condition is reported to Tcl
or to a widget or some other C code, and there is not usually any
obvious way for that code to report the error to the user.
In these cases the code calls \fBTcl_BackgroundError\fR with an
\fIinterp\fR argument identifying the interpreter in which the
error occurred.  At the time \fBTcl_BackgroundError\fR is invoked,
the interpreter's result is expected to contain an error message.

'\"
'\" Copyright (c) 1996-1997 Sun Microsystems, Inc.
'\" Copyright (c) 1997-2000 Ajuba Solutions.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
'\" RCS: @(#) $Id: CrtChannel.3,v 1.36 2007/10/24 14:29:37 dkf Exp $
.so man.macros
.TH Tcl_CreateChannel 3 8.4 Tcl "Tcl Library Procedures"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
Tcl_CreateChannel, Tcl_GetChannelInstanceData, Tcl_GetChannelType, Tcl_GetChannelName, Tcl_GetChannelHandle, Tcl_GetChannelMode, Tcl_GetChannelBufferSize, Tcl_SetChannelBufferSize, Tcl_NotifyChannel, Tcl_BadChannelOption, Tcl_ChannelName, Tcl_ChannelVersion, Tcl_ChannelBlockModeProc, Tcl_ChannelCloseProc, Tcl_ChannelClose2Proc, Tcl_ChannelInputProc, Tcl_ChannelOutputProc, Tcl_ChannelSeekProc, Tcl_ChannelWideSeekProc, Tcl_ChannelTruncateProc, Tcl_ChannelSetOptionProc, Tcl_ChannelGetOptionProc, Tcl_ChannelWatchProc, Tcl_ChannelGetHandleProc, Tcl_ChannelFlushProc, Tcl_ChannelHandlerProc, Tcl_ChannelThreadActionProc, Tcl_IsChannelShared, Tcl_IsChannelRegistered, Tcl_CutChannel, Tcl_SpliceChannel, Tcl_IsChannelExisting, Tcl_ClearChannelHandlers, Tcl_GetChannelThread, Tcl_ChannelBuffered \- procedures for creating and manipulating channels
.SH SYNOPSIS

.CS
    bad option "-blah": should be one of -blocking,
    -buffering, -buffersize, -eofchar, -translation,
    -peername, or -sockname
.CE
when called with \fIoptionList\fR="peername sockname"
.PP
.QW blah
is the \fIoptionName\fR argument and
.QW "<specific options>"
is a space separated list of specific option words.
The function takes good care of inserting minus signs before
each option, commas after, and an
.QW or
before the last option.
.SH "OLD CHANNEL TYPES"
The original (8.3.1 and below) \fBTcl_ChannelType\fR structure contains
the following fields:
.PP
.CS
typedef struct Tcl_ChannelType {
        char *\fItypeName\fR;

'\"
'\" Copyright (c) 1995-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: CrtSlave.3,v 1.17 2007/10/24 14:29:37 dkf Exp $
'\" 
.so man.macros
.TH Tcl_CreateSlave 3 7.6 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_IsSafe, Tcl_MakeSafe, Tcl_CreateSlave, Tcl_GetSlave, Tcl_GetMaster, Tcl_GetInterpPath, Tcl_CreateAlias, Tcl_CreateAliasObj, Tcl_GetAlias, Tcl_GetAliasObj, Tcl_ExposeCommand, Tcl_HideCommand \- manage multiple Tcl interpreters, aliases and hidden commands
.SH SYNOPSIS

.SH ARGUMENTS
.AS "const char *const" **targetInterpPtr out
.AP Tcl_Interp *interp in
Interpreter in which to execute the specified command.
.AP "const char" *slaveName in
Name of slave interpreter to create or manipulate.
.AP int isSafe in
If non-zero, a
.QW safe
slave that is suitable for running untrusted code
is created, otherwise a trusted slave is created.
.AP Tcl_Interp *slaveInterp in
Interpreter to use for creating the source command for an alias (see
below).
.AP "const char" *slaveCmd in
Name of source command for alias.
.AP Tcl_Interp *targetInterp in

then the \fBresult\fR field of the interpreter contains an error message.
.PP
\fBTcl_CreateSlave\fR creates a new interpreter as a slave of \fIinterp\fR.
It also creates a slave command named \fIslaveName\fR in \fIinterp\fR which 
allows \fIinterp\fR to manipulate the new slave. 
If \fIisSafe\fR is zero, the command creates a trusted slave in which Tcl
code has access to all the Tcl commands.
If it is \fB1\fR, the command creates a
.QW safe
slave in which Tcl code has access only to set of Tcl commands defined as
.QW "Safe Tcl" ;
see the manual entry for the Tcl \fBinterp\fR command for details.
If the creation of the new slave interpreter failed, \fBNULL\fR is returned.
.PP
\fBTcl_IsSafe\fR returns \fB1\fR if \fIinterp\fR is
.QW safe
(was created with the \fBTCL_SAFE_INTERPRETER\fR flag specified),
\fB0\fR otherwise.
.PP
\fBTcl_MakeSafe\fR marks \fIinterp\fR as
.QW safe ,
so that future
calls to \fBTcl_IsSafe\fR will return 1.  It also removes all known
potentially-unsafe core functionality (both commands and variables)
from \fIinterp\fR.  However, it cannot know what parts of an extension
or application are safe and does not make any attempt to remove those
parts, so safety is not guaranteed after calling \fBTcl_MakeSafe\fR.
Callers will want to take care with their use of \fBTcl_MakeSafe\fR
to avoid false claims of safety.  For many situations, \fBTcl_CreateSlave\fR

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: DString.3,v 1.14 2007/10/24 14:29:37 dkf Exp $
'\" 
.so man.macros
.TH Tcl_DString 3 7.4 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_DStringInit, Tcl_DStringAppend, Tcl_DStringAppendElement, Tcl_DStringStartSublist, Tcl_DStringEndSublist, Tcl_DStringLength, Tcl_DStringValue, Tcl_DStringSetLength, Tcl_DStringTrunc, Tcl_DStringFree, Tcl_DStringResult, Tcl_DStringGetResult \- manipulate dynamic strings
.SH SYNOPSIS

\fBTcl_DStringAppendElement\fR is similar to \fBTcl_DStringAppend\fR
except that it doesn't take a \fIlength\fR argument (it appends
all of \fIelement\fR) and it converts the string to a proper list element
before appending.
\fBTcl_DStringAppendElement\fR adds a separator space before the
new list element unless the new list element is the first in a
list or sub-list (i.e. either the current string is empty, or it
contains the single character
.QW { ,
or the last two characters of the current string are
.QW " {" ).
\fBTcl_DStringAppendElement\fR returns a pointer to the
characters of the new string.
.PP
\fBTcl_DStringStartSublist\fR and \fBTcl_DStringEndSublist\fR can be
used to create nested lists.
To append a list element that is itself a sublist, first
call \fBTcl_DStringStartSublist\fR, then call \fBTcl_DStringAppendElement\fR

'\"
'\" Copyright (c) 1997-1998 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: Encoding.3,v 1.26 2007/10/24 14:29:37 dkf Exp $
'\" 
.so man.macros
.TH Tcl_GetEncoding 3 "8.1" Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_GetEncoding, Tcl_FreeEncoding, Tcl_GetEncodingFromObj, Tcl_ExternalToUtfDString, Tcl_ExternalToUtf, Tcl_UtfToExternalDString, Tcl_UtfToExternal, Tcl_WinTCharToUtf, Tcl_WinUtfToTChar, Tcl_GetEncodingName, Tcl_SetSystemEncoding, Tcl_GetEncodingNameFromEnvironment, Tcl_GetEncodingNames, Tcl_CreateEncoding, Tcl_GetEncodingSearchPath, Tcl_SetEncodingSearchPath, Tcl_GetDefaultEncodingDir, Tcl_SetDefaultEncodingDir \- procedures for creating and using encodings
.SH SYNOPSIS

ignored.
.PP
\fBTcl_GetDefaultEncodingDir\fR and \fBTcl_SetDefaultEncodingDir\fR
are obsolete interfaces best replaced with calls to
\fBTcl_GetEncodingSearchPath\fR and \fBTcl_SetEncodingSearchPath\fR.
They are called to access and set the first element of the \fIsearchPath\fR
list.  Since Tcl searches \fIsearchPath\fR for encoding data files in
list order, these routines establish the
.QW default
directory in which to find encoding data files.
.VE 8.5
.SH "ENCODING FILES"
Space would prohibit precompiling into Tcl every possible encoding
algorithm, so many encodings are stored on disk as dynamically-loadable
encoding files.  This behavior also allows the user to create additional
encoding files that can be loaded using the same mechanism.  These
encoding files contain information about the tables and/or escape
sequences used to map between an external encoding and Unicode.  The
external encoding may consist of single-byte, multi-byte, or double-byte
characters.  
.PP
Each dynamically-loadable encoding is represented as a text file.  The
initial line of the file, beginning with a
.QW #
symbol, is a comment
that provides a human-readable description of the file.  The next line
identifies the type of encoding file.  It can be one of the following
letters:
.IP "[1] \fBS\fR"
A single-byte encoding, where one character is always one byte long in the
encoding.  An example is \fBiso8859-1\fR, used by many European languages.
.IP "[2] \fBD\fR"

.PP
In the file, the first column represents an option and the second column
is the associated value.  \fBinit\fR is a string to emit or expect before
the first character is converted, while \fBfinal\fR is a string to emit
or expect after the last character.  All other options are names of
table-based encodings; the associated value is the escape-sequence that
marks that encoding.  Tcl syntax is used for the values; in the above
example, for instance,
.QW \fB{}\fR
represents the empty string and
.QW \fB\ex1b\fR
represents character 27.
.PP
When \fBTcl_GetEncoding\fR encounters an encoding \fIname\fR that has not
been loaded, it attempts to load an encoding file called \fIname\fB.enc\fR
from the \fBencoding\fR subdirectory of each directory that Tcl searches
for its script library.  If the encoding file exists, but is
malformed, an error message will be left in \fIinterp\fR.
.SH KEYWORDS
utf, encoding, convert

'\"
'\" Copyright (c) 1989-1993 The Regents of the University of California.
'\" Copyright (c) 1994-1997 Sun Microsystems, Inc.
'\" Copyright (c) 2000 Scriptics Corporation.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: Eval.3,v 1.24 2007/10/24 14:29:37 dkf Exp $
'\" 
.so man.macros
.TH Tcl_Eval 3 8.1 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_EvalObjEx, Tcl_EvalFile, Tcl_EvalObjv, Tcl_Eval, Tcl_EvalEx, Tcl_GlobalEval, Tcl_GlobalEvalObj, Tcl_VarEval, Tcl_VarEvalVA \- execute Tcl scripts
.SH SYNOPSIS

.PP
\fBTcl_EvalFile\fR reads the file given by \fIfileName\fR and evaluates
its contents as a Tcl script.  It returns the same information as
\fBTcl_EvalObjEx\fR.
If the file couldn't be read then a Tcl error is returned to describe
why the file couldn't be read.
The eofchar for files is '\\32' (^Z) for all platforms.
If you require a
.QW ^Z
in code for string comparison, you can use
.QW \e032
or
.QW \eu001a ,
which will be safely substituted by the Tcl interpreter into
.QW ^Z .
.PP
\fBTcl_EvalObjv\fR executes a single pre-parsed command instead of a
script.  The \fIobjc\fR and \fIobjv\fR arguments contain the values
of the words for the Tcl command, one word in each object in
\fIobjv\fR.  \fBTcl_EvalObjv\fR evaluates the command and returns
a completion code and result just like \fBTcl_EvalObjEx\fR.
The caller of \fBTcl_EvalObjv\fR has to manage the reference count of the

'\"
'\" Copyright (c) 1989-1993 The Regents of the University of California.
'\" Copyright (c) 1994-1997 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: ExprLong.3,v 1.12 2007/10/24 14:29:37 dkf Exp $
'\" 
.so man.macros
.TH Tcl_ExprLong 3 7.0 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_ExprLong, Tcl_ExprDouble, Tcl_ExprBoolean, Tcl_ExprString \- evaluate an expression
.SH SYNOPSIS

an error is returned.
.PP
\fBTcl_ExprBoolean\fR stores a 0/1 integer value at \fI*booleanPtr\fR.
If the expression's actual value is an integer or floating-point
number, then they store 0 at \fI*booleanPtr\fR if
the value was zero and 1 otherwise.
If the expression's actual value is a non-numeric string then
it must be one of the values accepted by \fBTcl_GetBoolean\fR such as
.QW yes
or
.QW no ,
or else an error occurs.
.PP
\fBTcl_ExprString\fR returns the value of the expression as a
string stored in the interpreter's result.

.SH "SEE ALSO"
Tcl_ExprLongObj, Tcl_ExprDoubleObj, Tcl_ExprBooleanObj, Tcl_ExprObj

.SH KEYWORDS
boolean, double, evaluate, expression, integer, object, string

'\"
'\" Copyright (c) 1996-1997 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: ExprLongObj.3,v 1.6 2007/10/24 14:29:37 dkf Exp $
'\" 
.so man.macros
.TH Tcl_ExprLongObj 3 8.0 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_ExprLongObj, Tcl_ExprDoubleObj, Tcl_ExprBooleanObj, Tcl_ExprObj \- evaluate an expression
.SH SYNOPSIS

an error is returned.
.PP
\fBTcl_ExprBooleanObj\fR stores a 0/1 integer value at \fI*booleanPtr\fR.
If the expression's actual value is an integer or floating-point
number, then they store 0 at \fI*booleanPtr\fR if
the value was zero and 1 otherwise.
If the expression's actual value is a non-numeric string then
it must be one of the values accepted by \fBTcl_GetBoolean\fR such as
.QW yes
or
.QW no ,
or else an error occurs.
.PP
If \fBTcl_ExprObj\fR successfully evaluates the expression,
it stores a pointer to the Tcl object
containing the expression's value at \fI*resultPtrPtr\fR.
In this case, the caller is responsible for calling
\fBTcl_DecrRefCount\fR to decrement the object's reference count
when it is finished with the object.

.SH "SEE ALSO"
Tcl_ExprLong, Tcl_ExprDouble, Tcl_ExprBoolean, Tcl_ExprString, Tcl_GetObjResult

.SH KEYWORDS
boolean, double, evaluate, expression, integer, object, string

'\"
'\" Copyright (c) 2001 Vincent Darley
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: FileSystem.3,v 1.58 2007/10/24 14:29:37 dkf Exp $
'\" 
.so man.macros
.TH Filesystem 3 8.4 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_FSRegister, Tcl_FSUnregister, Tcl_FSData, Tcl_FSMountsChanged, Tcl_FSGetFileSystemForPath, Tcl_FSGetPathType, Tcl_FSCopyFile, Tcl_FSCopyDirectory, Tcl_FSCreateDirectory, Tcl_FSDeleteFile, Tcl_FSRemoveDirectory, Tcl_FSRenameFile, Tcl_FSListVolumes, Tcl_FSEvalFile, Tcl_FSEvalFileEx, Tcl_FSLoadFile, Tcl_FSMatchInDirectory, Tcl_FSLink, Tcl_FSLstat, Tcl_FSUtime, Tcl_FSFileAttrsGet, Tcl_FSFileAttrsSet, Tcl_FSFileAttrStrings, Tcl_FSStat, Tcl_FSAccess, Tcl_FSOpenFileChannel, Tcl_FSGetCwd, Tcl_FSChdir, Tcl_FSPathSeparator, Tcl_FSJoinPath, Tcl_FSSplitPath, Tcl_FSEqualPaths, Tcl_FSGetNormalizedPath, Tcl_FSJoinToPath, Tcl_FSConvertToPathType, Tcl_FSGetInternalRep, Tcl_FSGetTranslatedPath, Tcl_FSGetTranslatedStringPath, Tcl_FSNewNativePath, Tcl_FSGetNativePath, Tcl_FSFileSystemInfo, Tcl_AllocStatBuf \- procedures to interact with any filesystem
.SH SYNOPSIS

its contents as a Tcl script.  It returns the same information as
\fBTcl_EvalObjEx\fR.
If \fIencodingName\fR is NULL, the system encoding is used for
reading the file contents.
If the file couldn't be read then a Tcl error is returned to describe
why the file couldn't be read.
The eofchar for files is '\\32' (^Z) for all platforms.
If you require a
.QW ^Z
in code for string comparison, you can use
.QW \e032
or
.QW \eu001a ,
which will be safely substituted by the Tcl interpreter into
.QW ^Z .
\fBTcl_FSEvalFile\fR is a simpler version of
\fBTcl_FSEvalFileEx\fR that always uses the system encoding
when reading the file.
.VE 8.5
.PP
\fBTcl_FSLoadFile\fR dynamically loads a binary code file into memory and
returns the addresses of two procedures within that file, if they are

a particular filesystem with a file path, and deal with the internal
handling of path representations, for example copying and freeing such
representations.
.SS TYPENAME
.PP
The \fItypeName\fR field contains a null-terminated string that
identifies the type of the filesystem implemented, e.g.
.QW native ,
.QW zip
or
.QW vfs .
.SS "STRUCTURE LENGTH"
.PP
The \fIstructureLength\fR field is generally implemented as
\fIsizeof(Tcl_Filesystem)\fR, and is there to allow easier
binary backwards compatibility if the size of the structure
changes in a future Tcl release.
.SS VERSION

'\"
'\" Copyright (c) 1989-1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: GetInt.3,v 1.11 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH Tcl_GetInt 3 "" Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_GetInt, Tcl_GetDouble, Tcl_GetBoolean \- convert from string to integer, double, or boolean
.SH SYNOPSIS

desired type then \fBTCL_ERROR\fR is returned, an error message is left
in the interpreter's result, and nothing is stored at *\fIintPtr\fR
or *\fIdoublePtr\fR or *\fIboolPtr\fR.
.PP
\fBTcl_GetInt\fR expects \fIsrc\fR to consist of a collection
of integer digits, optionally signed and optionally preceded by
white space.  If the first two characters of \fIsrc\fR
after the optional white space and sign are
.QW 0x
then \fIsrc\fR is expected to be in hexadecimal form;  otherwise,
if the first such character is
.QW 0
then \fIsrc\fR
is expected to be in octal form;  otherwise, \fIsrc\fR is
expected to be in decimal form.
.PP
\fBTcl_GetDouble\fR expects \fIsrc\fR to consist of a floating-point
number, which is:  white space;  a sign; a sequence of digits;  a
decimal point;  a sequence of digits;  the letter
.QW e ;
a signed decimal exponent ; and more white space.
Any of the fields may be omitted, except that
the digits either before or after the decimal point must be present
and if the
.QW e
is present then it must be followed by the exponent number.
.PP
\fBTcl_GetBoolean\fR expects \fIsrc\fR to specify a boolean
value.  If \fIsrc\fR is any of \fB0\fR, \fBfalse\fR,
\fBno\fR, or \fBoff\fR, then \fBTcl_GetBoolean\fR stores a zero
value at \fI*boolPtr\fR.
If \fIsrc\fR is any of \fB1\fR, \fBtrue\fR, \fByes\fR, or \fBon\fR,
then 1 is stored at \fI*boolPtr\fR.
Any of these values may be abbreviated, and upper-case spellings
are also acceptable.

.SH KEYWORDS
boolean, conversion, double, floating-point, integer

'\"
'\" Copyright (c) 1989-1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: Hash.3,v 1.22 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH Tcl_Hash 3 "" Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_InitHashTable, Tcl_InitCustomHashTable, Tcl_InitObjHashTable, Tcl_DeleteHashTable, Tcl_CreateHashEntry, Tcl_DeleteHashEntry, Tcl_FindHashEntry, Tcl_GetHashValue, Tcl_SetHashValue, Tcl_GetHashKey, Tcl_FirstHashEntry, Tcl_NextHashEntry, Tcl_HashStats \- procedures to manage hash tables
.SH SYNOPSIS

may have the same value.  Keys can take one of four forms: strings,
one-word values, integer arrays, or custom keys defined by a
Tcl_HashKeyType structure (See section \fBTHE TCL_HASHKEYTYPE
STRUCTURE\fR below). All of the keys in a given table have the same
form, which is specified when the table is initialized.
.PP
The value of a hash table entry can be anything that fits in the same
space as a
.QW "char *"
pointer.  Values for hash table entries are
managed entirely by clients, not by the hash module itself.  Typically
each entry's value is a pointer to a data structure managed by client
code.
.PP
Hash tables grow gracefully as the number of entries increases, so
that there are always less than three entries per hash bucket, on
average. This allows for fast lookups regardless of the number of

\fIKeyType\fR must have one of the following values:
.IP \fBTCL_STRING_KEYS\fR 25
Keys are null-terminated strings.
They are passed to hashing routines using the address of the
first character of the string.
.IP \fBTCL_ONE_WORD_KEYS\fR 25
Keys are single-word values;  they are passed to hashing routines
and stored in hash table entries as
.QW "char *"
values.
The pointer value is the key;  it need not (and usually doesn't)
actually point to a string.
.IP \fBTCL_CUSTOM_TYPE_KEYS\fR 25
Keys are of arbitrary type, and are stored in the entry. Hashing
and comparison is determined by \fItypePtr\fR. The Tcl_HashKeyType 
structure is described in the section 
\fBTHE TCL_HASHKEYTYPE STRUCTURE\fR below.
.IP \fBTCL_CUSTOM_PTR_KEYS\fR 25
Keys are pointers to an arbitrary type, and are stored in the entry. Hashing
and comparison is determined by \fItypePtr\fR. The Tcl_HashKeyType 
structure is described in the section 
\fBTHE TCL_HASHKEYTYPE STRUCTURE\fR below.
.IP \fIother\fR 25
If \fIkeyType\fR is not one of the above,
then it must be an integer value greater than 1.
In this case the keys will be arrays of
.QW int
values, where \fIkeyType\fR gives the number of ints in each key.
This allows structures to be used as keys.
All keys must have the same size.
Array keys are passed into hashing functions using the address
of the first int in the array.
.PP
\fBTcl_DeleteHashTable\fR deletes all of the entries in a hash
table and frees up the memory associated with the table's

.PP
\fBTcl_FindHashEntry\fR is similar to \fBTcl_CreateHashEntry\fR
except that it doesn't create a new entry if the key doesn't exist;
instead, it returns NULL as result.
.PP
\fBTcl_GetHashValue\fR and \fBTcl_SetHashValue\fR are used to
read and write an entry's value, respectively.
Values are stored and retrieved as type
.QW ClientData ,
which is
large enough to hold a pointer value.  On almost all machines this is
large enough to hold an integer value too.
.PP
\fBTcl_GetHashKey\fR returns the key for a given hash table entry,
either as a pointer to a string, a one-word (e.g.
.QW "char *" )
key, or as a pointer to the first word of an array of integers, depending
on the \fIkeyType\fR used to create a hash table.
In all cases \fBTcl_GetHashKey\fR returns a result with type
.QW "char *" .
When the key is a string or array, the result of \fBTcl_GetHashKey\fR
points to information in the table entry;  this information will
remain valid until the entry is deleted or its table is deleted.
.PP
\fBTcl_FirstHashEntry\fR and \fBTcl_NextHashEntry\fR may be used
to scan all of the entries in a hash table. A structure of type
.QW Tcl_HashSearch ,
provided by the client, is used to keep track of progress through the
table. \fBTcl_FirstHashEntry\fR initializes the search record and
returns the first entry in the table (or NULL if the table is
empty).
Each subsequent call to \fBTcl_NextHashEntry\fR returns the
next entry in the table or
NULL if the end of the table has been reached.
A call to \fBTcl_FirstHashEntry\fR followed by calls to
\fBTcl_NextHashEntry\fR will return each of the entries in

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: LinkVar.3,v 1.13 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH Tcl_LinkVar 3 7.5 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_LinkVar, Tcl_UnlinkVar, Tcl_UpdateLinkedVar \- link Tcl variable to C variable
.SH SYNOPSIS

'\" FIXME! Use bignums instead.
attempts to write non-integer values into \fIvarName\fR will be
rejected with Tcl errors.
.VE 8.5
.TP
\fBTCL_LINK_BOOLEAN\fR
The C variable is of type \fBint\fR.
If its value is zero then it will read from Tcl as
.QW 0 ;
otherwise it will read from Tcl as
.QW 1 .
Whenever \fIvarName\fR is
modified, the C variable will be set to a 0 or 1 value.
Any value written into the Tcl variable must have a proper boolean
form acceptable to \fBTcl_GetBooleanFromObj\fR;  attempts to write
non-boolean values into \fIvarName\fR will be rejected with
Tcl errors.
.TP
\fBTCL_LINK_STRING\fR
The C variable is of type \fBchar *\fR.
If its value is not NULL then it must be a pointer to a string
allocated with \fBTcl_Alloc\fR or \fBckalloc\fR.
Whenever the Tcl variable is modified the current C string will be
freed and new memory will be allocated to hold a copy of the variable's
new value.
If the C variable contains a NULL pointer then the Tcl variable
will read as
.QW NULL .
.PP
If the \fBTCL_LINK_READ_ONLY\fR flag is present in \fItype\fR then the
variable will be read-only from Tcl, so that its value can only be
changed by modifying the C variable.
Attempts to write the variable from Tcl will be rejected with errors.
.PP
\fBTcl_UnlinkVar\fR removes the link previously set up for the

'\"
'\" Copyright (c) 1998-1999 Scriptics Corporation
'\" Copyright (c) 1995-1997 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: Notifier.3,v 1.18 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH Notifier 3 8.1 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_CreateEventSource, Tcl_DeleteEventSource, Tcl_SetMaxBlockTime, Tcl_QueueEvent, Tcl_ThreadQueueEvent, Tcl_ThreadAlert, Tcl_GetCurrentThread, Tcl_DeleteEvents, Tcl_InitNotifier, Tcl_FinalizeNotifier, Tcl_WaitForEvent, Tcl_AlertNotifier, Tcl_SetTimer, Tcl_ServiceAll, Tcl_ServiceEvent, Tcl_GetServiceMode, Tcl_SetServiceMode \- the event queue and notifier interfaces
.SH SYNOPSIS

\fBTcl_InitNotifier\fR initializes the notifier state and returns
a handle to the notifier state.  Tcl calls this
procedure when initializing a Tcl interpreter.  Similarly,
\fBTcl_FinalizeNotifier\fR shuts down the notifier, and is
called by \fBTcl_Finalize\fR when shutting down a Tcl interpreter.
.PP
\fBTcl_WaitForEvent\fR is the lowest-level procedure in the notifier;
it is responsible for waiting for an
.QW interesting
event to occur or
for a given time to elapse.  Before \fBTcl_WaitForEvent\fR is invoked,
each of the event sources' setup procedure will have been invoked.
The \fItimePtr\fR argument to
\fBTcl_WaitForEvent\fR gives the maximum time to block for an event,
based on calls to \fBTcl_SetMaxBlockTime\fR made by setup procedures
and on other information (such as the \fBTCL_DONT_WAIT\fR bit in
\fIflags\fR).

'\"
'\" Copyright (c) 1989-1993 The Regents of the University of California.
'\" Copyright (c) 1994-1997 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: PrintDbl.3,v 1.8 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH Tcl_PrintDouble 3 8.0 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_PrintDouble \- Convert floating value to string
.SH SYNOPSIS

.BE

.SH DESCRIPTION
.PP
\fBTcl_PrintDouble\fR generates a string that represents the value
of \fIvalue\fR and stores it in memory at the location given by
\fIdst\fR.  It uses \fB%g\fR format to generate the string, with one
special twist: the string is guaranteed to contain either a
.QW .
or an
.QW e
so that it doesn't look like an integer. Where \fB%g\fR would generate
an integer with no decimal point, \fBTcl_PrintDouble\fR adds
.QW .0 .
.VS 8.5
.PP
If the \fBtcl_precision\fR value is non-zero, the result will have
precisely that many digits of significance.  If the value is zero
(the default), the result will have the fewest digits needed to
represent the number in such a way that \fBTcl_NewDoubleObj\fR
will generate the same number when presented with the given string.
IEEE semantics of rounding to even apply to the conversion.
.VE

.SH KEYWORDS
conversion, double-precision, floating-point, string

'\"
'\" Copyright (c) 1994 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\" Copyright (c) 1998-1999 Scriptics Corporation
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: RegExp.3,v 1.24 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH Tcl_RegExpMatch 3 8.1 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_RegExpMatch, Tcl_RegExpCompile, Tcl_RegExpExec, Tcl_RegExpRange, Tcl_GetRegExpFromObj, Tcl_RegExpMatchObj, Tcl_RegExpExecObj, Tcl_RegExpGetInfo \- Pattern matching with regular expressions
.SH SYNOPSIS

long as the internal representation of \fIpatObj\fR refers to the
compiled form.  The \fIeflags\fR argument is a bit-wise OR of
zero or more of the following flags that control the compilation of
\fIpatObj\fR:
.RS 2
.TP
\fBTCL_REG_ADVANCED\fR
Compile advanced regular expressions
.PQ ARE s .
This mode corresponds to the normal regular expression syntax accepted by the
Tcl \fBregexp\fR and \fBregsub\fR commands.
.TP
\fBTCL_REG_EXTENDED\fR
Compile extended regular expressions
.PQ ERE s .
This mode corresponds to the regular expression syntax recognized by Tcl 8.0
and earlier versions. 
.TP
\fBTCL_REG_BASIC\fR
Compile basic regular expressions
.PQ BRE s .
This mode corresponds to the regular expression syntax recognized by common
Unix utilities like \fBsed\fR and \fBgrep\fR.  This is the default if no flags
are specified.
.TP
\fBTCL_REG_EXPANDED\fR
Compile the regular expression (basic, extended, or advanced) using an
expanded syntax that allows comments and whitespace.  This mode causes
non-backslashed non-bracket-expression white
space and #-to-end-of-line comments to be ignored.
.TP
\fBTCL_REG_QUOTE\fR
Compile a literal string, with all characters treated as ordinary characters.
.TP
\fBTCL_REG_NOCASE\fR
Compile for matching that ignores upper/lower case distinctions.
.TP
\fBTCL_REG_NEWLINE\fR
Compile for newline-sensitive matching.  By default, newline is a
completely ordinary character with no special meaning in either
regular expressions or strings.  With this flag,
.QW [^
bracket expressions and
.QW .
never match newline,
.QW ^
matches an empty string
after any newline in addition to its normal function, and
.QW $
matches an empty string before any newline in addition to its normal
function. \fBREG_NEWLINE\fR is the bit-wise OR of \fBREG_NLSTOP\fR and
\fBREG_NLANCH\fR.
.TP
\fBTCL_REG_NLSTOP\fR
Compile for partial newline-sensitive matching, with the behavior of
.QW [^
bracket expressions and
.QW .
affected, but not the behavior of
.QW ^
and
.QW $ .
In this mode,
.QW [^
bracket expressions and
.QW .

never match newline.
.TP
\fBTCL_REG_NLANCH\fR
Compile for inverse partial newline-sensitive matching, with the behavior of
.QW ^
and
.QW $
(the
.QW anchors )
affected, but not the behavior of
.QW [^
bracket expressions and
.QW . .
In this mode
.QW ^
matches an empty string after any newline in addition to its normal function,
and
.QW $
matches an empty string before any newline in addition to its normal function.
.TP
\fBTCL_REG_NOSUB\fR
Compile for matching that reports only success or failure,
not what was matched.  This reduces compile overhead and may improve
performance.  Subsequent calls to \fBTcl_RegExpGetInfo\fR or
\fBTcl_RegExpRange\fR will not report any match information.
.TP

offset value.  Instead the behavior of the anchors is explicitly
controlled by the \fIeflags\fR argument, which is a bit-wise OR of
zero or more of the following flags:
.RS 2
.TP
\fBTCL_REG_NOTBOL\fR
The starting character will not be treated as the beginning of a
line or the beginning of the string, so
.QW ^
will not match there. Note that this flag has no effect on how
.QW \fB\eA\fR
matches.
.TP
\fBTCL_REG_NOTEOL\fR
The last character in the string will not be treated as the end of a
line or the end of the string, so
.QW $
will not match there. Note that this flag has no effect on how
.QW \fB\eZ\fR
matches.
.RE
.PP
\fBTcl_RegExpGetInfo\fR retrieves information about the last match
performed with a given regular expression \fIregexp\fR.  The
\fIinfoPtr\fR argument contains a pointer to a structure that is
defined as follows:
.PP

'\"
'\" Copyright (c) 1989-1993 The Regents of the University of California.
'\" Copyright (c) 1994-1997 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: SetResult.3,v 1.15 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH Tcl_SetResult 3 8.0 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_SetObjResult, Tcl_GetObjResult, Tcl_SetResult, Tcl_GetStringResult, Tcl_AppendResult, Tcl_AppendResultVA, Tcl_AppendElement, Tcl_ResetResult, Tcl_FreeResult \- manipulate Tcl result
.SH SYNOPSIS

\fIelement\fR will be extracted as a single element.
Under normal conditions, \fBTcl_AppendElement\fR will add a space
character to \fIinterp\fR's result just before adding the new
list element, so that the list elements in the result are properly
separated.
However if the new list element is the first in a list or sub-list
(i.e. \fIinterp\fR's current result is empty, or consists of the
single character
.QW { ,
or ends in the characters
.QW " {" )
then no space is added.
.PP
\fBTcl_FreeResult\fR performs part of the work
of \fBTcl_ResetResult\fR.
It frees up the memory associated with \fIinterp\fR's result.
It also sets \fIinterp->freeProc\fR to zero, but doesn't
change \fIinterp->result\fR or clear error state.
\fBTcl_FreeResult\fR is most commonly used when a procedure

'\"
'\" Copyright (c) 1989-1993 The Regents of the University of California.
'\" Copyright (c) 1994-1997 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: SetVar.3,v 1.13 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH Tcl_SetVar 3 8.1 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_SetVar2Ex, Tcl_SetVar, Tcl_SetVar2, Tcl_ObjSetVar2, Tcl_GetVar2Ex, Tcl_GetVar, Tcl_GetVar2, Tcl_ObjGetVar2, Tcl_UnsetVar, Tcl_UnsetVar2 \- manipulate Tcl variables
.SH SYNOPSIS

.TP
\fBTCL_LIST_ELEMENT\fR
If this bit is set, then \fInewValue\fR is converted to a valid
Tcl list element before setting (or appending to) the variable.
A separator space is appended before the new list element unless
the list element is going to be the first element in a list or
sublist (i.e. the variable's current value is empty, or contains
the single character
.QW { ,
or ends in
.QW " }" ).
When appending, the original value of the variable must also be
a valid list, so that the operation is the appending of a new
list element onto a list.
.PP
\fBTcl_GetVar\fR and \fBTcl_GetVar2\fR
return the current value of a variable.
The arguments to these procedures are treated in the same way

'\"
'\" Copyright (c) 1989-1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: SplitList.3,v 1.10 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH Tcl_SplitList 3 8.0 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_SplitList, Tcl_Merge, Tcl_ScanElement, Tcl_ConvertElement, Tcl_ScanCountedElement, Tcl_ConvertCountedElement \- manipulate Tcl lists
.SH SYNOPSIS

used to generate a portion of an argument for a Tcl command.
In this case, surrounding \fIsrc\fR with curly braces would cause
the command not to be parsed correctly.
.PP
.VS 8.5
By default, \fBTcl_ConvertElement\fR will use quoting in its output
to be sure the first character of an element is not the hash
character (i.e.
.QW # ).
This is to be sure the first element of any list
passed to \fBeval\fR is not mis-parsed as the beginning of a comment.
When a list element is not the first element of a list, this quoting
is not necessary.  When the caller can be sure that the element is
not the first element of a list, it can disable quoting of the leading
hash character by OR-ing the flag value returned by \fBTcl_ScanElement\fR
with \fBTCL_DONT_QUOTE_HASH\fR.
.VE 8.5

'\"
'\" Copyright (c) 2001 by ActiveState Corporation
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: StdChannels.3,v 1.11 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH "Standard Channels" 3 7.5 Tcl "Tcl Library Procedures"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
Tcl_StandardChannels \- How the Tcl library deals with the standard channels

.PP
Standard channels are initialized by the Tcl library in three cases:
when explicitly requested, when implicitly required before returning
channel information, or when implicitly required during registration
of a new channel.
.PP
These cases differ in how they handle unavailable platform- specific
standard channels.  (A channel is not
.QW available
if it could not be successfully opened; for example, in a Tcl
application run as a Windows NT service.)
.TP
1)
A single standard channel is initialized when it is explicitly
specified in a call to \fBTcl_SetStdChannel\fR.  The states of the
other standard channels are unaffected.
.RS
.PP

'\"
'\" Copyright (c) 1989-1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: StrMatch.3,v 1.10 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH Tcl_StringMatch 3 8.1 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_StringMatch, Tcl_StringCaseMatch \- test whether a string matches a pattern
.SH SYNOPSIS

.BE

.SH DESCRIPTION
.PP
This utility procedure determines whether a string matches
a given pattern.  If it does, then \fBTcl_StringMatch\fR returns
1.  Otherwise \fBTcl_StringMatch\fR returns 0.  The algorithm
used for matching is the same algorithm used in the
.QW "string match"
Tcl command and is similar to the algorithm used by the C-shell
for file name matching;  see the Tcl manual entry for details.
.PP
In \fBTcl_StringCaseMatch\fR, the algorithm is the same, but you have
the option to make the matching case-insensitive.  If you choose this
(by passing \fBnocase\fR as 1), then the string and pattern are
essentially matched in the lower case.

.SH KEYWORDS
match, pattern, string

'\"
'\" Copyright (c) 2001 Donal K. Fellows
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: SubstObj.3,v 1.4 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH Tcl_SubstObj 3 8.4 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_SubstObj \- perform substitutions on Tcl objects
.SH SYNOPSIS

.PP
When the \fBTCL_SUBST_VARIABLES\fR bit is set in \fIflags\fR,
sequences that look like variable substitutions for Tcl commands are
replaced by the contents of the named variable.
.PP
When the \fBTCL_SUBST_COMMANDS\fR bit is set in \fIflags\fR, sequences
that look like command substitutions for Tcl commands are replaced by
the result of evaluating that script.  Where an uncaught
.QW "continue exception"
occurs during the evaluation of a command substitution, an
empty string is substituted for the command.  Where an uncaught
.QW "break exception"
occurs during the evaluation of a command substitution, the
result of the whole substitution on \fIobjPtr\fR will be truncated at
the point immediately before the start of the command substitution,
and no characters will be added to the result or substitutions
performed after that point.

.SH "SEE ALSO"
subst(n)

.SH KEYWORDS
backslash substitution, command substitution, variable substitution

'\" 
'\" Copyright (c) 1992-1999 Karl Lehenbauer and Mark Diekhans.
'\" Copyright (c) 2000 by Scriptics Corporation.
'\" All rights reserved.
'\" 
'\" RCS: @(#) $Id: TCL_MEM_DEBUG.3,v 1.8 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH TCL_MEM_DEBUG 3 8.1 Tcl "Tcl Library Procedures"
.BS
.SH NAME
TCL_MEM_DEBUG \- Compile-time flag to enable Tcl memory debugging
.BE

and the Tcl \fBmemory\fR command can be used to validate and examine
memory usage.

.SH "GUARD ZONES"
.PP
When memory debugging is enabled, whenever a call to \fBckalloc\fR is
made, slightly more memory than requested is allocated so the memory debugging
code can keep track of the allocated memory, and eight-byte
.QW "guard zones"
are placed in front of and behind the space that will be
returned to the caller.  (The sizes of the guard zones are defined by the
C #define \fBLOW_GUARD_SIZE\fR and #define \fBHIGH_GUARD_SIZE\fR
in the file \fIgeneric/tclCkalloc.c\fR -- it can
be extended if you suspect large overwrite problems, at some cost in
performance.)  A known pattern is written into the guard zones and, on
a call to \fBckfree\fR, the guard zones of the space being freed are
checked to see if either zone has been modified in any way.  If one
has been, the guard bytes and their new contents are identified, and a
.QW "low guard failed"
or
.QW "high guard failed"
message is issued.  The
.QW "guard failed"
message includes the address of the memory packet and
the file name and line number of the code that called \fBckfree\fR.
This allows you to detect the common sorts of one-off problems, where
not enough space was allocated to contain the data written, for
example.

.SH "DEBUGGING DIFFICULT MEMORY CORRUPTION PROBLEMS"
.PP

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: Tcl.n,v 1.15 2007/10/24 14:29:38 dkf Exp $
'\"
.so man.macros
.TH Tcl n "8.5" Tcl "Tcl Built-In Commands"
.BS
.SH NAME
Tcl \- Tool Command Language
.SH SYNOPSIS

in any way it likes, such as an integer, variable name, list,
or Tcl script.
Different commands interpret their words differently.
.IP "[3] \fBWords.\fR"
Words of a command are separated by white space (except for
newlines, which are command separators).
.IP "[4] \fBDouble quotes.\fR"
If the first character of a word is double-quote
.PQ \N'34'
then the word is terminated by the next double-quote character.
If semi-colons, close brackets, or white space characters
(including newlines) appear between the quotes then they are treated
as ordinary characters and included in the word.
Command substitution, variable substitution, and backslash substitution
are performed on the characters between the quotes as described below.
The double-quotes are not retained as part of the word.
.VS 8.5 br
.IP "[5] \fBArgument expansion.\fR"
If a word starts with the string
.QW {*}
followed by a non-whitespace character, then the leading
.QW {*}
is removed and the rest of the word is parsed and substituted as any
other word. After substitution, the word is parsed again without
substitutions, and its words are added to the command being
substituted. For instance,
.QW "cmd a {*}{b c} d {*}{e f}"
is equivalent to
.QW "cmd a b c d e f" . 
.VE 8.5
.IP "[6] \fBBraces.\fR"
If the first character of a word is an open brace
.PQ {
and rule [5] does not apply, then
the word is terminated by the matching close brace
.PQ } "" .
Braces nest within the word: for each additional open
brace there must be an additional close brace (however,
if an open brace or close brace within the word is
quoted with a backslash then it is not counted in locating the
matching close brace).
No substitutions are performed on the characters between the
braces except for backslash-newline substitutions described
below, nor do semi-colons, newlines, close brackets,
or white space receive any special interpretation.
The word will consist of exactly the characters between the
outer braces, not including the braces themselves.
.IP "[7] \fBCommand substitution.\fR"
If a word contains an open bracket
.PQ [
then Tcl performs \fIcommand substitution\fR.
To do this it invokes the Tcl interpreter recursively to process
the characters following the open bracket as a Tcl script.
The script may contain any number of commands and must be terminated
by a close bracket
.PQ ] "" .
The result of the script (i.e. the result of its last command) is
substituted into the word in place of the brackets and all of the
characters between them.
There may be any number of command substitutions in a single word.
Command substitution is not performed on words enclosed in braces.
.IP "[8] \fBVariable substitution.\fR"
If a word contains a dollar-sign
.PQ $
followed by one of the forms described below, then Tcl performs \fIvariable
substitution\fR:  the dollar-sign and the following characters are
replaced in the word by the value of a variable.
Variable substitution may take any of the following forms:
.RS
.TP 15
\fB$\fIname\fR
\fIName\fR is the name of a scalar variable;  the name is a sequence

\fIName\fR is the name of a scalar variable.  It may contain any
characters whatsoever except for close braces.
.LP
There may be any number of variable substitutions in a single word.
Variable substitution is not performed on words enclosed in braces.
.RE
.IP "[9] \fBBackslash substitution.\fR"
If a backslash
.PQ \e
appears within a word then \fIbackslash substitution\fR occurs.
In all cases but those described below the backslash is dropped and
the following character is treated as an ordinary
character and included in the word.
This allows characters such as double quotes, close brackets,
and dollar signs to be included in words without triggering
special processing.
The following table lists the backslash sequences that are

and tabs after the newline.  This backslash sequence is unique in that it
is replaced in a separate pre-pass before the command is actually parsed.
This means that it will be replaced even when it occurs between braces,
and the resulting space will be treated as a word separator if it isn't
in braces or quotes.
.TP 7
\e\e
Backslash
.PQ \e "" .
.TP 7
\e\fIooo\fR 
.
The digits \fIooo\fR (one, two, or three of them) give an eight-bit octal 
value for the Unicode character that will be inserted.  The upper bits of the
Unicode character will be 0.
.TP 7

sixteen-bit hexadecimal value for the Unicode character that will be
inserted.
.LP
Backslash substitution is not performed on words enclosed in braces,
except for backslash-newline as described above.
.RE
.IP "[10] \fBComments.\fR"
If a hash character
.PQ #
appears at a point where Tcl is
expecting the first character of the first word of a command,
then the hash character and the characters that follow it, up
through the next newline, are treated as a comment and ignored.
The comment character only has significance when it appears
at the beginning of a command.
.IP "[11] \fBOrder of substitution.\fR"
Each character is processed exactly once by the Tcl interpreter

'\"
'\" Copyright (c) 1994 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\" Copyright (c) 2000 Ajuba Solutions.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: Tcl_Main.3,v 1.12 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH Tcl_Main 3 8.4 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_Main, Tcl_SetMainLoop \- main program and event loop definition for Tcl-based applications
.SH SYNOPSIS

.AP Tcl_MainLoopProc *mainLoopProc in
Address of an application-specific event loop procedure.
.BE

.SH DESCRIPTION
.PP
\fBTcl_Main\fR can serve as the main program for Tcl-based shell
applications.  A
.QW "shell application"
is a program like tclsh or wish that supports both interactive interpretation
of Tcl and evaluation of a script contained in a file given as
a command line argument.  \fBTcl_Main\fR is offered as a convenience
to developers of shell applications, so they do not have to 
reproduce all of the code for proper initialization of the Tcl
library and interactive shell operation.  Other styles of embedding
Tcl in an application are not supported by \fBTcl_Main\fR.  Those
must be achieved by calling lower level functions in the Tcl library

.PP
In either mode, \fBTcl_Main\fR will define in its master interpreter
the Tcl variables \fIargc\fR, \fIargv\fR, \fIargv0\fR, and
\fItcl_interactive\fR, as described in the documentation for \fBtclsh\fR.
.PP
When it has finished its own initialization, but before it processes
commands, \fBTcl_Main\fR calls the procedure given by the
\fIappInitProc\fR argument.  This procedure provides a
.QW hook
for the application to perform its own initialization of the interpreter
created by \fBTcl_Main\fR, such as defining application-specific
commands.  The procedure must have an interface that matches the
type \fBTcl_AppInitProc\fR:
.CS
typedef int Tcl_AppInitProc(Tcl_Interp *\fIinterp\fR);
.CE

'\"
'\" Copyright (c) 1989-1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: TraceVar.3,v 1.16 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH Tcl_TraceVar 3 7.4 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_TraceVar, Tcl_TraceVar2, Tcl_UntraceVar, Tcl_UntraceVar2, Tcl_VarTraceInfo, Tcl_VarTraceInfo2 \- monitor accesses to a variable
.SH SYNOPSIS

.SH "UNDEFINED VARIABLES"
.PP
It is legal to set a trace on an undefined variable.
The variable will still appear to be undefined until the
first time its value is set.
If an undefined variable is traced and then unset, the unset will fail
with an error,
.QW "no such variable" ,
but the trace procedure will still be invoked.

.SH "TCL_TRACE_DESTROYED FLAG"
.PP
In an unset callback to \fIproc\fR, the \fBTCL_TRACE_DESTROYED\fR bit
is set in \fIflags\fR if the trace is being removed as part
of the deletion.
Traces on a variable are always removed whenever the variable

'\"
'\" Copyright (c) 1989-1993 The Regents of the University of California.
'\" Copyright (c) 1994-1998 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: Translate.3,v 1.10 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH Tcl_TranslateFileName 3 8.1 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_TranslateFileName \- convert file name to native form and replace tilde with home directory
.SH SYNOPSIS
.nf
\fB#include <tcl.h>\fR
.sp
char *
\fBTcl_TranslateFileName\fR(\fIinterp\fR, \fIname\fR, \fIbufferPtr\fR)
.SH ARGUMENTS
.AS Tcl_DString *bufferPtr in/out
.AP Tcl_Interp *interp in
Interpreter in which to report an error, if any.
.AP "const char" *name in
File name, which may start with a
.QW ~ .
.AP Tcl_DString *bufferPtr in/out
If needed, this dynamic string is used to store the new file name.
At the time of the call it should be uninitialized or free.  The
caller must eventually call \fBTcl_DStringFree\fR to free up
anything stored here.
.BE

'\"
'\" Copyright (c) 1994-1997 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: WrongNumArgs.3,v 1.9 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH Tcl_WrongNumArgs 3 8.0 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_WrongNumArgs \- generate standard error message for wrong number of arguments
.SH SYNOPSIS

\fBTcl_WrongNumArgs\fR is a utility procedure that is invoked by
command procedures when they discover that they have received the
wrong number of arguments.  \fBTcl_WrongNumArgs\fR generates a
standard error message and stores it in the result object of
\fIinterp\fR.  The message includes the \fIobjc\fR initial
elements of \fIobjv\fR plus \fImessage\fR.  For example, if
\fIobjv\fR consists of the values \fBfoo\fR and \fBbar\fR,
\fIobjc\fR is 1, and \fImessage\fR is
.QW "\fBfileName count\fR"
then \fIinterp\fR's result object will be set to the following
string:
.CS
wrong # args: should be "foo fileName count"
.CE
If \fIobjc\fR is 2, the result will be set to the following string:
.CS

'\"
'\" Copyright (c) 1990-1994 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: after.n,v 1.8 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH after n 7.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
after \- Execute a command after a time delay

proc doOneStep {} {
   if {[::my_calc::one_step]} {
      \fBafter idle\fR [list \fBafter\fR 0 doOneStep]
   }
}
doOneStep
.CE

.SH "SEE ALSO"
concat(n), interp(n), update(n), vwait(n)

.SH KEYWORDS
cancel, delay, idle callback, sleep, time

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: append.n,v 1.7 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH append n "" Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
append \- Append to variable

of variable \fIvarName\fR.  If \fIvarName\fR doesn't exist,
it is given a value equal to the concatenation of all the
\fIvalue\fR arguments.
The result of this command is the new value stored in variable
\fIvarName\fR.
This command provides an efficient way to build up long
variables incrementally.
For example,
.QW "\fBappend a $b\fR"
is much more efficient than
.QW "\fBset a $a$b\fR" ,
especially when \fB$a\fR is long.
.SH EXAMPLE
Building a string of comma-separated numbers piecemeal using a loop.
.CS
set var 0
for {set i 1} {$i<=10} {incr i} {
   \fBappend\fR var "," $i
}
puts $var
# Prints 0,1,2,3,4,5,6,7,8,9,10
.CE

.SH "SEE ALSO"
concat(n), lappend(n)

.SH KEYWORDS
append, variable

the \fBvariable\fR command or the \fBupvar\fR command.
.PP
The invocation of \fBapply\fR adds a call frame to Tcl's evaluation stack
(the stack of frames accessed via \fBuplevel\fR). The execution of \fIbody\fR
proceeds in this call frame, in the namespace given by \fInamespace\fR or
in the global namespace if none was specified. If given, \fInamespace\fR is
interpreted relative to the global namespace even if its name does not start
with
.QW :: . 
.PP
The semantics of \fBapply\fR can also be described by:
.PP
.CS
proc apply {fun args} {
   set len [llength $fun]
   if {($len < 2) || ($len > 3)} {

   return -options $opt $res
}
.CE
.SH EXAMPLES
This shows how to make a simple general command that applies a transformation
to each element of a list.
.CS
.ta 2i
proc map {lambda list} {
   set result {}
   foreach $item $list {
      lappend result [\fBapply\fR $lambda $item]
   }
   return $result
}
map {x {return [string length $x]:$x}} {a bb ccc dddd}
	 \fB\(->\fI 1:a 2:bb 3:ccc 4:dddd\fR
map {x {expr {$x**2 + 3*$x - 2}}} {-4 -3 -2 -1 0 1 2 3 4}
	 \fB\(->\fI 2 -2 -4 -4 -2 2 8 16 26\fR
.CE
.PP
The \fBapply\fR command is also useful for defining callbacks for use in the
\fBtrace\fR command:
.CS
.ta 2i
set vbl "123abc"
trace add variable vbl write {\fBapply\fR {v1 v2 op} {
   upvar 1 $v1 v
   puts "updated variable to \e"$v\e""
}}
set vbl 123
	 \fB\(->\fI updated variable to "123"\fR
set vbl abc
	 \fB\(->\fI updated variable to "abc"\fR
.CE
.SH "SEE ALSO"
proc(n), uplevel(n)
.SH KEYWORDS
argument, procedure, anonymous function

'\"
'\" Copyright (c) 1993-1994 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: array.n,v 1.17 2007/10/25 09:25:27 dkf Exp $
'\" 
.so man.macros
.TH array n 8.3 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
array \- Manipulate array variables

   blue  4
   white 9
}

foreach {color count} [\fBarray get\fR colorcount] {
   puts "Color: $color Count: $count"
}
  \(-> Color: blue Count: 4
    Color: white Count: 9
    Color: green Count: 5
    Color: red Count: 1

foreach color [\fBarray names\fR colorcount] {
   puts "Color: $color Count: $colorcount($color)"
}
  \(-> Color: blue Count: 4
    Color: white Count: 9
    Color: green Count: 5
    Color: red Count: 1

foreach color [lsort [\fBarray names\fR colorcount]] {
   puts "Color: $color Count: $colorcount($color)"
}
  \(-> Color: blue Count: 4
    Color: green Count: 5
    Color: red Count: 1
    Color: white Count: 9

\fBarray statistics\fR colorcount
  \(-> 4 entries in table, 4 buckets
    number of buckets with 0 entries: 1
    number of buckets with 1 entries: 2
    number of buckets with 2 entries: 1
    number of buckets with 3 entries: 0
    number of buckets with 4 entries: 0
    number of buckets with 5 entries: 0
    number of buckets with 6 entries: 0
    number of buckets with 7 entries: 0
    number of buckets with 8 entries: 0
    number of buckets with 9 entries: 0
    number of buckets with 10 or more entries: 0
    average search distance for entry: 1.2
.CE

.SH "SEE ALSO"
list(n), string(n), variable(n), trace(n), foreach(n)

.SH KEYWORDS
array, element names, search

'\"
'\" Copyright (c) 1990-1994 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: bgerror.n,v 1.10 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH bgerror n 7.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
bgerror \- Command invoked to process background errors

proc bgerror {message} {
    set timestamp [clock format [clock seconds]]
    set fl [open mylog.txt {WRONLY CREAT APPEND}]
    puts $fl "$timestamp: bgerror in $::argv '$message'"
    close $fl
}
.CE

.SH "SEE ALSO"
after(n), interp(n), tclvars(n)

.SH KEYWORDS
background error, reporting

'\"
'\" Copyright (c) 1997 by Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: binary.n,v 1.31 2007/10/25 14:07:32 dkf Exp $
'\" 
.so man.macros
.TH binary n 8.0 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
binary \- Insert and extract fields from binary strings

\fBbinary format\fR B5B* 11100 111000011010
.CE
will return a string equivalent to \fB\\xe0\\xe1\\xa0\fR.
.RE
.IP \fBh\fR 5
Stores a string of \fIcount\fR hexadecimal digits in low-to-high
within each byte in the output string.  \fIArg\fR must contain a
sequence of characters in the set
.QW 0123456789abcdefABCDEF .
The resulting bytes are emitted in first to last order with the hex digits
being formatted in low-to-high order within each byte.  If \fIarg\fR
has fewer than \fIcount\fR digits, then zeros will be used for the
remaining digits.  If \fIarg\fR has more than the specified number of
digits, the extra digits will be ignored.  If \fIcount\fR is
\fB*\fR, then all of the digits in \fIarg\fR will be formatted.  If
\fIcount\fR is omitted, then one digit will be formatted.  If the
number of digits formatted does not end at a byte boundary, the

\fIcount\fR is a non-negative decimal integer or \fB*\fR, which
normally indicates that all of the remaining items in the data are to
be used.  If there are not enough bytes left after the current cursor
position to satisfy the current field specifier, then the
corresponding variable is left untouched and \fBbinary scan\fR returns
immediately with the number of variables that were set.  If there are
not enough arguments for all of the fields in the format string that
consume arguments, then an error is generated. The flag character
.QW u
may be given to cause some types to be read as unsigned values. The flag
is accepted for all field types but is ignored for non-integer fields.
.PP
A similar example as with \fBbinary format\fR should explain the
relation between field specifiers and arguments in case of the binary
scan subcommand:
.CS

long data size values.  In doing this, values that have their high
bit set (0x80 for chars, 0x8000 for shorts, 0x80000000 for ints),
will be sign extended.  Thus the following will occur:
.CS
set signShort [\fBbinary format\fR s1 0x8000]
\fBbinary scan\fR $signShort s1 val; \fI# val == 0xFFFF8000\fR
.CE
If you require unsigned values you can include the
.QW u
flag character following the field type. For example, to read an
unsigned short value:
.CS
set signShort [\fBbinary format\fR s1 0x8000]
\fBbinary scan\fR $signShort su1 val; \fI# val == 0x00008000\fR
.CE
.PP
Each type-count pair moves an imaginary cursor through the binary data,
reading bytes from the current position.  The cursor is initially

.CS
\fBbinary scan\fR "abc efghi  \\000" A* var1
.CE
will return \fB1\fR with \fBabc efghi\fR stored in \fIvar1\fR.
.RE
.IP \fBb\fR 5
The data is turned into a string of \fIcount\fR binary digits in
low-to-high order represented as a sequence of
.QW 1
and
.QW 0
characters.  The data bytes are scanned in first to last order with
the bits being taken in low-to-high order within each byte.  Any extra
bits in the last byte are ignored.  If \fIcount\fR is \fB*\fR, then
all of the remaining bits in \fIstring\fR will be scanned.  If
\fIcount\fR is omitted, then one bit will be scanned.  For example,
.RS
.CS

.CE
will return \fB2\fR with \fB01110\fR stored in \fIvar1\fR and
\fB1000011100000101\fR stored in \fIvar2\fR.
.RE
.IP \fBH\fR 5
The data is turned into a string of \fIcount\fR hexadecimal digits in
high-to-low order represented as a sequence of characters in the set
.QW 0123456789abcdef .
The data bytes are scanned in first to last
order with the hex digits being taken in high-to-low order within each
byte. Any extra bits in the last byte are ignored. If \fIcount\fR is
\fB*\fR, then all of the remaining hex digits in \fIstring\fR will be
scanned. If \fIcount\fR is omitted, then one hex digit will be
scanned. For example,
.RS
.CS

    if {![\fBbinary scan\fR [read $channel 4] I length]} {
        error "missing length"
    }
    set data [read $channel $length]
    return [encoding convertfrom utf-8 $data]
}
.CE

.SH "SEE ALSO"
format(n), scan(n), tclvars(n)

.SH KEYWORDS
binary, format, scan

'\"
'\" Copyright (c) 1993-1994 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: break.n,v 1.8 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH break n "" Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
break \- Abort looping command

for {set x 0} {$x<10} {incr x} {
   if {$x > 5} {
      \fBbreak\fR
   }
   puts "x is $x"
}
.CE

.SH "SEE ALSO"
catch(n), continue(n), for(n), foreach(n), return(n), while(n)

.SH KEYWORDS
abort, break, loop

'\"
'\" Copyright (c) 1993-1994 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\" Contributions from Don Porter, NIST, 2003.  (not subject to US copyright)
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: catch.n,v 1.14 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH catch n "8.5" Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
catch \- Evaluate script and trap exceptional returns

    puts stderr "Could not open $someFile for writing\\n$fid"
    exit 1
}
.CE
.PP
There are more complex examples of \fBcatch\fR usage in the
documentation for the \fBreturn\fR command.

.SH "SEE ALSO" 
break(n), continue(n), dict(n), error(n), return(n), tclvars(n)

.SH KEYWORDS
catch, error

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: cd.n,v 1.7 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH cd n "" Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
cd \- Change working directory

.CE
.PP
Change to the directory \fBlib\fR that is a sibling directory of the
current one:
.CS
\fBcd\fR ../lib
.CE

.SH "SEE ALSO"
filename(n), glob(n), pwd(n)

.SH KEYWORDS
working directory

'\" 
'\" Copyright (c) 2005-2006 Donal K. Fellows
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
'\" RCS: @(#) $Id: chan.n,v 1.12 2007/10/25 14:07:32 dkf Exp $
.so man.macros
.TH chan n 8.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
chan \- Read, write and manipulate channels
.SH SYNOPSIS

\fInot\fR made.  If \fIinputChan\fR is closed, then all data already
queued for \fIoutputChan\fR is written out.
.PP
Note that \fIinputChan\fR can become readable during a background
copy.  You should turn off any \fBchan event\fR or \fBfileevent\fR
handlers during a background copy so those handlers do not interfere
with the copy.  Any I/O attempted by a \fBchan event\fR or
\fBfileevent\fR handler will get a
.QW "channel busy"
error.
.PP
\fBChan copy\fR translates end-of-line sequences in \fIinputChan\fR
and \fIoutputChan\fR according to the \fB\-translation\fR option for
these channels (see \fBchan configure\fR above).  The translations
mean that the number of bytes read from \fIinputChan\fR can be
different than the number of bytes written to \fIoutputChan\fR.  Only
the number of bytes written to \fIoutputChan\fR is reported, either as

returned as the result of the \fBchan create\fR command, and the
channel is open. Use either \fBclose\fR or \fBchan close\fR to remove
the channel.
.RS
.PP
The argument \fImode\fR specifies if the new channel is opened for
reading, writing, or both. It has to be a list containing any of the
strings
.QW "\fBread\fR"
or
.QW "\fBwrite\fR" .
The list must have at least one
element, as a channel you can neither write to nor read from makes no
sense. The handler command for the new channel must support the chosen
mode, or an error is thrown.
.PP
The command prefix is executed in the global namespace, at the top of
call stack, following the appending of arguments as described in the
\fBreflectedchan\fR manual page. Command resolution happens at the

writable.  File event handlers are most commonly used to allow data to
be received from another process on an event-driven basis, so that the
receiver can continue to interact with the user or with other channels
while waiting for the data to arrive.  If an application invokes
\fBchan gets\fR or \fBchan read\fR on a blocking channel when there is
no input data available, the process will block; until the input data
arrives, it will not be able to service other events, so it will
appear to the user to
.QW "freeze up" .
With \fBchan event\fR, the
process can tell when data is present and only invoke \fBchan gets\fR
or \fBchan read\fR when they won't block.
.PP
A channel is considered to be readable if there is unread data
available on the underlying device.  A channel is also considered to
be readable if there is unread data in an input buffer, except in the
special case where the most recent attempt to read from the channel

.
Produces a list of all channel names. If \fIpattern\fR is specified,
only those channel names that match it (according to the rules of
\fBstring match\fR) will be returned.
.TP
\fBchan pending \fImode channelId\fR
.
Depending on whether \fImode\fR is
.QW "input"
or
.QW "output" ,
returns the number of 
bytes of input or output (respectively) currently buffered 
internally for \fIchannelId\fR (especially useful in a readable event 
callback to impose application-specific limits on input line lengths to avoid
a potential denial-of-service attack where a hostile user crafts
an extremely long line that exceeds the available memory to buffer it).
Returns -1 if the channel was not opened for the mode in question.
.TP
\fBchan postevent \fIchannelId eventSpec\fR
.
This subcommand is used by command handlers specified with \fBchan
create\fR. It notifies the channel represented by the handle
\fIchannelId\fR that the event(s) listed in the \fIeventSpec\fR have
occurred. The argument has to be a list containing any of the strings
.QW "\fBread\fR"
and
.QW "\fBwrite\fR" .
The list must contain at least one
element as it does not make sense to invoke the command if there are
no events to post.
.RS
.PP
Note that this subcommand can only be used with channel handles that
were created/opened by \fBchan create\fR. All other channels will
cause this subcommand to report an error.

'\"
'\" Generated from file './doc/clock.dt' by tcllib/doctools with format 'nroff'
'\" Copyright (c) 2004 Kevin B. Kenny <[email protected]>. All rights reserved.
'\"
.so man.macros
.TH "clock" n 8.5 Tcl "Tcl Built-In Commands"
.BS
.SH NAME
clock \- Obtain and manipulate dates and times
.SH "SYNOPSIS"
package require \fBTcl 8.5\fR
.sp
\fBclock add\fR \fItimeVal\fR ?\fIcount unit...\fR? ?\fI\-option value\fR?
.sp
\fBclock clicks\fR ?\fI\-option\fR?
.sp
\fBclock format\fR \fItimeVal\fR ?\fI\-option value\fR...?
.sp
\fBclock microseconds\fR 
.sp
\fBclock milliseconds\fR 
.sp
\fBclock scan\fR \fIinputString\fR ?\fI\-option value\fR...?
.sp
\fBclock seconds\fR 
.sp
.BE
.SH "DESCRIPTION"
.PP
The \fBclock\fR command performs several operations that obtain and
manipulate values that represent times.  The command supports several
subcommands that determine what action is carried out by the command.
.TP
\fBclock add\fR \fItimeVal\fR ?\fIcount unit...\fR? ?\fI\-option value\fR?
Adds a (possibly negative) offset to a time that is expressed as an
integer number of seconds.  See \fBCLOCK ARITHMETIC\fR for a full description.
.TP
\fBclock clicks\fR ?\fI\-option\fR?
If no \fI\-option\fR argument is supplied, returns a high-resolution
time value as a system-dependent integer value.  The unit of the value
is system-dependent but should be the highest resolution clock available
on the system such as a CPU cycle counter.  See \fBHIGH RESOLUTION TIMERS\fR for a full description.
.sp
If the \fI\-option\fR argument is \fI\-milliseconds\fR, then the command
is synonymous with \fBclock milliseconds\fR (see below).  This
usage is obsolete, and \fBclock milliseconds\fR is to be
considered the preferred way of obtaining a count of milliseconds.
.sp
If the \fI\-option\fR argument is \fI\-microseconds\fR, then the command
is synonymous with \fBclock microseconds\fR (see below).  This
usage is obsolete, and \fBclock microseconds\fR is to be
considered the preferred way of obtaining a count of microseconds.
.TP
\fBclock format\fR \fItimeVal\fR ?\fI\-option value\fR...?
Formats a time that is expressed as an integer number of seconds into a format
intended for consumption by users or external programs.
See \fBFORMATTING TIMES\fR for a full description.
.TP
\fBclock microseconds\fR 
Returns the current time as an integer number of microseconds.  See \fBHIGH RESOLUTION TIMERS\fR for a full description.
.TP
\fBclock milliseconds\fR 
Returns the current time as an integer number of milliseconds.  See \fBHIGH RESOLUTION TIMERS\fR for a full description.
.TP
\fBclock scan\fR \fIinputString\fR ?\fI\-option value\fR...?
Scans a time that is expressed as a character string and produces an
integer number of seconds.
See \fBSCANNING TIMES\fR for a full description.
.TP
\fBclock seconds\fR 
Returns the current time as an integer number of seconds.
.SS "PARAMETERS"

One of the words, \fBseconds\fR, \fBminutes\fR, \fBhours\fR,
\fBdays\fR, \fBweeks\fR, \fBmonths\fR, or \fByears\fR, or
any unique prefix of such a word. Used in conjunction with \fIcount\fR
to identify an interval of time, for example, \fI3 seconds\fR or
\fI1 year\fR.
.SS "OPTIONS"
.TP
\fB\-base\fR time
Specifies that any relative times present in a \fBclock scan\fR command
are to be given relative to \fItime\fR.  \fItime\fR must be expressed as
a count of nominal seconds from the epoch time of 1 January 1970, 00:00 UTC.
.TP
\fB\-format\fR format
Specifies the desired output format for \fBclock format\fR or the
expected input format for \fBclock scan\fR.  The \fIformat\fR string consists
of any number of characters other than the per-cent sign
.PQ \fI%\fR
interspersed with any number of \fIformat groups\fR, which are two-character
sequences beginning with the per-cent sign.  The permissible format groups,
and their interpretation, are described under \fBFORMAT GROUPS\fR.
.RS
.PP
On \fBclock format\fR, the default format is
.CS
%a %b %d %H:%M:%S %z %Y
.CE
.PP
On \fBclock scan\fR, the lack of a \fI\-format\fR option indicates that a
.QW "free format scan"
is requested; see \fBFREE FORM SCAN\fR for a description of what happens.
.RE
.TP
\fB\-gmt\fR boolean
If \fIboolean\fR is true, specifies that a time specified to \fBclock add\fR,
\fBclock format\fR or \fBclock scan\fR should be processed in
UTC.  If \fIboolean\fR is false, the processing defaults to the local time
zone.  This usage is obsolete; the correct current usage is to
specify the UTC time zone with
.QW "\fB\-timezone\fR \fI:UTC\fR"
or any of the equivalent ways to specify it.
.TP
\fB\-locale\fR localeName
Specifies that locale-dependent scanning and formatting (and date arithmetic
for dates preceding the adoption of the Gregorian calendar) is to be done in
the locale identified by \fIlocaleName\fR.  The locale name may be any of
the locales acceptable to the \fBmsgcat\fR package, or it may be the special
name \fIsystem\fR, which represents the current locale of the process, or
the null string, which represents Tcl's default locale.
.sp
The effect of locale on scanning and formatting is discussed in the
descriptions of the individual format groups under \fBFORMAT GROUPS\fR.
The effect of locale on clock arithmetic is discussed under
\fBCLOCK ARITHMETIC\fR.
.TP
\fB\-timezone\fR zoneName
Specifies that clock arithmetic, formatting, and scanning are to be done
according to the rules for the time zone specified by \fIzoneName\fR.
The permissible values, and their interpretation, are discussed under
\fBTIME ZONES\fR.
On subcommands that expect a \fB\-timezone\fR argument, the default
is to use the \fIcurrent time zone\fR.  The current time zone is
determined, in order of preference, by:
.RS
.IP [1]
the environment variable \fBTCL_TZ\fR.
.IP [2]
the environment variable \fBTZ\fR.
.IP [3]
on Windows systems, the time zone settings from the Control Panel.
.RE
If none of these is present, the C \fBlocaltime\fR and \fBmktime\fR
functions are used to attempt to convert times between local and
Greenwich.  On 32-bit systems, this approach is likely to have bugs,
particularly for times that lie outside the window (approximately the
years 1902 to 2037) that can be represented in a 32-bit integer.
.SH "CLOCK ARITHMETIC"
The \fBclock add\fR command performs clock arithmetic on a value
(expressed as nominal seconds from the epoch time of 1 January 1970, 00:00 UTC)
given as its first argument.  The remaining arguments (other than the
possible \fB\-timezone\fR, \fB\-locale\fR and \fB\-gmt\fR options)
are integers and keywords in alternation, where the keywords are chosen
from \fBseconds\fR, \fBminutes\fR, \fBhours\fR,
\fBdays\fR, \fBweeks\fR, \fBmonths\fR, or \fByears\fR, or
any unique prefix of such a word.
.PP
Addition of seconds, minutes and hours is fairly straightforward;
the given time increment (times sixty for minutes, or 3600 for hours)

.SH "FORMATTING TIMES"
The \fBclock format\fR command produces times for display to a user
or writing to an external medium.  The command accepts times that are
expressed in seconds from the epoch time of 1 January 1970, 00:00 UTC,
as returned by \fBclock seconds\fR, \fBclock scan\fR, \fBclock add\fR,
\fBfile atime\fR or \fBfile mtime\fR.
.PP
If a \fB\-format\fR option is present, the following argument is
a string that specifies how the date and time are to be formatted.
The string consists
of any number of characters other than the per-cent sign
.PQ \fI%\fR
interspersed with any number of \fIformat groups\fR, which are two-character
sequences beginning with the per-cent sign.  The permissible format groups,
and their interpretation, are described under \fBFORMAT GROUPS\fR.
.PP
If a \fB\-timezone\fR option is present, the following
argument is a string that specifies the time zone in which the date and time
are to be formatted.  As an alternative to
.QW "\fB\-timezone\fR \fI:UTC\fR" ,
the obsolete usage
.QW "\fB\-gmt\fR \fItrue\fR"
may be used. See \fBTIME ZONES\fR for the permissible variants for the time
zone.
.PP
If a \fB\-locale\fR option is present, the following argument is
a string that specifies the locale in which the time is to be formatted,
in the same format that is used for the \fBmsgcat\fR package.  Note
that the default, if \fB\-locale\fR is not specified, is the root locale
\fB{}\fR rather than the current locale.  The current locale may
be obtained by using






.QW "\fB\-locale\fR \fBcurrent\fR" .

























In addition, some platforms support a \fBsystem\fR locale that
reflects the user's current choices.  For instance, on Windows, the
format that the user has selected from dates and times in the Control
Panel can be obtained by using the \fBsystem\fR locale.  On
platforms that do not define a user selection of date and time formats
separate from \fBLC_TIME\fR,
.QW "\fB\-locale\fR \fBsystem\fR"
is synonymous with
.QW "\fB\-locale\fR \fBcurrent\fR" .
.SH "SCANNING TIMES"
The \fBclock scan\fR command accepts times that are formatted as
strings and converts them to counts of seconds from the epoch time
of 1 January 1970, 00:00 UTC.  It normally takes a \fB\-format\fR
option that is followed by a string describing
the expected format of the input.  (See
\fBFREE FORM SCAN\fR for the effect of \fBclock scan\fR
without such an argument.)  The string consists of any number of
characters other than the per-cent sign
.PQ \fI%\fR "" ,
interspersed with any number of \fIformat groups\fR, which are two-character
sequences beginning with the per-cent sign.  The permissible format groups,
and their interpretation, are described under \fBFORMAT GROUPS\fR.
.PP
If a \fB\-timezone\fR option is present, the following
argument is a string that specifies the time zone in which the date and time
are to be interpreted.  As an alternative to
.QW "\fB\-timezone\fR \fI:UTC\fR" ,
the obsolete usage
.QW "\fB\-gmt\fR \fItrue\fR"
may be used. See \fBTIME ZONES\fR for the permissible variants for the time
zone.
.PP
If a \fB\-locale\fR option is present, the following argument is
a string that specifies the locale in which the time is to be interpreted,
in the same format that is used for the \fBmsgcat\fR package.  Note
that the default, if \fB\-locale\fR is not specified, is the root locale
.MT
rather than the current locale. The current locale may be obtained by using
.QW "\fB\-locale\fR \fBcurrent\fR" .
In addition, some platforms support a \fBsystem\fR locale that
reflects the user's current choices.  For instance, on Windows, the
format that the user has selected from dates and times in the Control
Panel can be obtained by using the \fBsystem\fR locale.  On
platforms that do not define a user selection of date and time formats
separate from \fBLC_TIME\fR,
.QW "\fB\-locale\fR \fBsystem\fR"
is synonymous with
.QW "\fB\-locale\fR \fBcurrent\fR" .
.PP
If a \fB\-base\fR option is present, the following argument is
a time (expressed in seconds from the epoch time) that is used as
a \fIbase time\fR for interpreting relative times.  If no
\fB\-base\fR option is present, the base time is the current time.
.PP
Scanning of times in fixed format works by determining three things:
the date, the time of day, and the time zone.  These three are then
combined into a point in time, which is returned as the number of seconds
from the epoch.
.PP
Before scanning begins, the format string is preprocessed

the minute of the hour, that group combines with the hour.  If the string
further contains a group specifying the second of the minute, that group
combines with the hour and minute.
.IP [3]
If the string contains neither a \fB%s\fR format group nor
a group specifying the hour of the day, then midnight (\fB00:00\fR, the start
of the given date) is used.
The time zone is determined by either the \fB\-timezone\fR or \fB\-gmt\fR
options, or by using the current time zone.
.PP
If a format string lacks a \fB%z\fR or \fB%Z\fR format group,
it is possible for the time to be ambiguous because it appears twice
in the same day, once without and once with Daylight Saving Time.
If this situation occurs, the first occurrence of the time is chosen.
(For this reason, it is wise to have the input string contain the

\fB%N\fR
On output, produces the number of the month (1-12) with one or two digits.
digits.  On input, accepts one or two digits, possibly with leading whitespace,
and interprets them as the number of the month.
.TP
\fB%Od\fR, \fB%Oe\fR, \fB%OH\fR, \fB%OI\fR, \fB%Ok\fR, \fB%Ol\fR, \fB%Om\fR, \fB%OM\fR, \fB%OS\fR, \fB%Ou\fR, \fB%Ow\fR, \fB%Oy\fR
All of these format groups are synonymous with their counterparts
without the
.QW \fBO\fR ,
except that the string is produced and parsed in the locale-dependent
alternative numerals.
.TP
\fB%p\fR
.
On output, produces an indicator for the part of the day, \fBAM\fR
or \fBPM\fR, appropriate to the given locale.  If the script of the
given locale supports multiple letterforms, lowercase is preferred.
On input, matches the representation \fBAM\fR or \fBPM\fR in
the given locale, in either case.
.TP
\fB%P\fR

time zone. This option should, in general, be used on input only when
parsing RFC822 dates. Other uses are fraught with ambiguity; for
instance, the string \fBBST\fR may represent British Summer Time or
Brazilian Standard Time. It is recommended that date/time strings for
use by computers use numeric time zones instead.
.TP
\fB%%\fR
On output, produces a literal
.QW \fB%\fR
character. On input, matches a literal
.QW \fB%\fR
character.
.TP
\fB%+\fR
Synonymous with
.QW "\fB%a %b %e %H:%M:%S %Z %Y\fR" .
.SH "TIME ZONES"
When the \fBclock\fR command is processing a local time, it has several
possible sources for the time zone to use.  In order of preference, they
are:
.IP [1]
A time zone specified inside a string being parsed and matched by a \fB%z\fR
or \fB%Z\fR format group.
.IP [2]
A time zone specified with the \fB\-timezone\fR option to the \fBclock\fR
command (or, equivalently, by
.QW "\fB\-gmt\fR \fB1\fR" ).
.IP [3]
A time zone specified in an environment variable \fBTCL_TZ\fR.
.IP [4]
A time zone specified in an environment variable \fBTZ\fR.
.IP [5]
The local time zone from the Control Panel on Windows systems.
.IP [6]

.PP
If the time zone begins with a colon, it is one of a
standardized list of names like \fB:America/New_York\fR
that give the rules for various locales.  A complete list
of the location names is too lengthy to be listed here.
On most Tcl installations, the definitions of the locations
are to be found in named files in the directory
.QW "\fI/no_backup/tools/lib/tcl8.5/clock/tzdata\fR" .
On some Unix systems, these
files are omitted, and the definitions are instead
obtained from system files in
.QW "\fI/usr/share/zoneinfo\fR" ,
.QW "\fI/usr/share/lib/zoneinfo\fR"
or
.QW "\fI/usr/local/etc/zoneinfo\fR" .
As a special case, the name \fB:localtime\fR refers to
the local time zone as defined by the C library.
.PP
A time zone string consisting of a plus or minus sign followed by
four or six decimal digits is interpreted as an offset in
hours, minutes, and seconds (if six digits are present) from
UTC.  The plus sign denotes a sign east of Greenwich;

Any other time zone string is processed by prefixing a colon and attempting
to use it as a location name, as above.
.SH "LOCALIZATION"
Developers wishing to localize the date and time formatting and parsing
are referred to \fIhttp://tip.tcl.tk/173\fR for a
specification.
.SH "FREE FORM SCAN"
If the \fBclock scan\fR command is invoked without a \fB\-format\fR
option, then it requests a \fIfree-form scan.\fR  \fI
This form of scan is deprecated.\fR  The reason for the deprecation
is that there are too many ambiguities. (Does the string
.QW 2000
represent a year, a time of day, or a quantity?)  No set of rules
for interpreting free-form dates and times has been found to
give unsurprising results in all cases.
.PP
If free-form scan is used, only the \fB\-base\fR and \fB\-gmt\fR
options are accepted.  The \fB\-timezone\fR and \fB\-locale\fR
options will result in an error if \fB\-format\fR is not supplied.
.PP
For the benefit of users who need to understand legacy code that
uses free-form scan, the documentation for how free-form scan
interprets a string is included here:
.PP
If only a time is
specified, the current date is assumed.  If the \fIinputString\fR
does not contain a
time zone mnemonic, the local time zone is assumed, unless the \fB\-gmt\fR
argument is true, in which case the clock value is calculated assuming
that the specified time is relative to Greenwich Mean Time.
\fB\-gmt\fR, if specified, affects only the computed time value; it does not
impact the interpretation of \fB\-base\fR.
.PP
If the \fB\-base\fR flag is specified, the next argument should contain
an integer clock value.  Only the date in this value is used, not the
time.  This is useful for determining the time on a specific day or
doing other date-relative conversions.
.PP
The \fIinputString\fR argument consists of zero or more specifications of the
following form:
.TP
\fItime\fR
A time of day, which is of the form: \fBhh?:mm?:ss?? ?meridian? ?zone?\fR
or \fBhhmm ?meridian? ?zone?\fR
If no meridian is specified, \fBhh\fR is interpreted on
a 24-hour clock.
.TP
\fIdate\fR
A specific month and day with optional year. The acceptable formats are
.QW "\fBmm/dd\fR?\fB/yy\fR?" ,
.QW "\fBmonthname dd\fR?\fB, yy\fR?" ,
.QW "\fBday, dd monthname \fR?\fByy\fR?" ,
.QW "\fBdd monthname yy\fR" ,
.QW "?\fBCC\fR?\fByymmdd\fR" ,
and
.QW "\fBdd-monthname-\fR?\fBCC\fR?\fByy\fR" .
The default year is the current year.  If the year is less
than 100, we treat the years 00-68 as 2000-2068 and the years 69-99
as 1969-1999.  Not all platforms can represent the years 38-70, so
an error may result if these years are used.
.TP
\fIISO 8601 point-in-time\fR
An ISO 8601 point-in-time specification, such as \fBCCyymmddThhmmss\fR,
where \fBT\fR is the literal
.QW T ,
.QW "\fBCCyymmdd hhmmss\fR" ,
or
.QW \fBCCyymmddThh:mm:ss\fR .
Note that only these three formats are accepted.
The command does \fInot\fR accept the full range of point-in-time
specifications specified in ISO8601.  Other formats can be recognized by
giving an explicit \fI\-format\fR option to the \fBclock scan\fR command.
.TP
\fIrelative time\fR
A specification relative to the current time.  The format is \fBnumber
unit\fR. Acceptable units are \fByear\fR, \fBfortnight\fR, 
\fBmonth\fR, \fBweek\fR, \fBday\fR,
\fBhour\fR, \fBminute\fR (or \fBmin\fR), and \fBsecond\fR (or \fBsec\fR).  The
unit can be specified as a singular or plural, as in \fB3 weeks\fR.

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: close.n,v 1.11 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH close n 7.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
close \- Close an open channel

    catch {
        uplevel 1 $script
    } result options
    \fBclose\fR $chan
    return -options $options $result
}
.CE

.SH "SEE ALSO"
file(n), open(n), socket(n), eof(n), Tcl_StandardChannels(3)

.SH KEYWORDS
blocking, channel, close, nonblocking

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: concat.n,v 1.8 2007/10/25 14:07:32 dkf Exp $
'\" 
.so man.macros
.TH concat n 8.3 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
concat \- Join lists together

It permits any number of arguments;
if no \fIarg\fRs are supplied, the result is an empty string.
.SH EXAMPLES
Although \fBconcat\fR will concatenate lists (so the command:
.CS
\fBconcat\fR a b {c d e} {f {g h}}
.CE
will return
.QW "\fBa b c d e f {g h}\fR"
as its result), it will also
concatenate things that are not lists, and hence the command:
.CS
\fBconcat\fR " a b {c   " d "  e} f"
.CE
will return
.QW "\fBa b {c d e} f\fR"
as its result.
.PP
Note that the concatenation does not remove spaces from the middle of
its arguments, so the command:
.CS
\fBconcat\fR "a   b   c" { d e f }
.CE
will return
.QW "\fBa   b   c d e f\fR"
(i.e. with three spaces between the
.QW \fBa\fR ,
the
.QW \fBb\fR
and the
.QW \fBc\fR ).
.SH "SEE ALSO"
append(n), eval(n)

.SH KEYWORDS
concatenate, join, lists

'\"
'\" Copyright (c) 1993-1994 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: continue.n,v 1.8 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH continue n "" Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
continue \- Skip to the next iteration of a loop

for {set x 0} {$x<10} {incr x} {
   if {$x == 5} {
      \fBcontinue\fR
   }
   puts "x is $x"
}
.CE

.SH "SEE ALSO"
break(n), for(n), foreach(n), return(n), while(n)

.SH KEYWORDS
continue, iteration, loop

'\"
'\" Copyright (c) 1997 Sun Microsystems, Inc.
'\" Copyright (c) 2001 ActiveState Corporation.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: dde.n,v 1.19 2007/10/25 14:07:32 dkf Exp $
'\" 
.so man.macros
.TH dde n 1.3 dde "Tcl Bundled Packages"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
dde \- Execute a Dynamic Data Exchange command

.PP
.SH "DDE COMMANDS"
.PP
The following commands are a subset of the full Dynamic Data Exchange
set of commands.
.TP
\fBdde servername \fR?\fB-force\fR? ?\fB-handler \fIproc\fR? ?\fB--\fR? ?\fItopic\fR?
.
\fBdde servername\fR registers the interpreter as a DDE server with
the service name \fBTclEval\fR and the topic name specified by \fItopic\fR.
If no \fItopic\fR is given, \fBdde servername\fR returns the name
of the current topic or the empty string if it is not registered as a
service. If the given \fItopic\fR name is already in use, then a
suffix of the form
.QW " #2"
or
.QW " #3"
is appended to the name to make it
unique. The command's result will be the name actually used. The
\fB\-force\fR option is used to force registration of precisely the
given \fItopic\fR name.
.IP
The \fB-handler\fR option specifies a Tcl procedure that will be called to
process calls to the dde server. If the package has been loaded into a
safe interpreter then a \fB-handler\fR procedure must be defined. The
procedure is called with all the arguments provided by the remote
call.
.TP
\fBdde execute\fR ?\fB\-async\fR? \fIservice topic data\fR
.
\fBdde execute\fR takes the \fIdata\fR and sends it to the server indicated
by \fIservice\fR with the topic indicated by \fItopic\fR. Typically,
\fIservice\fR is the name of an application, and \fItopic\fR is a file to
work on.  The \fIdata\fR field is given to the remote application.
Typically, the application treats the \fIdata\fR field as a script, and the
script is run in the application.  The \fB\-async\fR option requests
asynchronous invocation.  The command returns an error message if the
script did not run, unless the \fB\-async\fR flag was used, in which case
the command returns immediately with no error.
.TP
\fBdde poke \fIservice topic item data\fR
.
\fBdde poke\fR passes the \fIdata\fR to the server indicated by
\fIservice\fR using the \fItopic\fR and \fIitem\fR specified.  Typically,
\fIservice\fR is the name of an application.  \fItopic\fR is application
specific but can be a command to the server or the name of a file to work
on.  The \fIitem\fR is also application specific and is often not used, but
it must always be non-null.  The \fIdata\fR field is given to the remote
application.
.TP
\fBdde request\fR ?\fB\-binary\fR? \fIservice topic item\fR
.
\fBdde request\fR is typically used to get the value of something; the
value of a cell in Microsoft Excel or the text of a selection in
Microsoft Word. \fIservice\fR is typically the name of an application,
\fItopic\fR is typically the name of the file, and \fIitem\fR is
application-specific. The command returns the value of \fIitem\fR as
defined in the application.  Normally this is interpreted to be a
string with terminating null.  If \fB\-binary\fR is specified, the
result is returned as a byte array.
.TP
\fBdde services \fIservice topic\fR
.
\fBdde services\fR returns a list of service-topic pairs that
currently exist on the machine. If \fIservice\fR and \fItopic\fR are
both empty strings ({}), then all service-topic pairs currently
available on the system are returned. If \fIservice\fR is empty and
\fItopic\fR is not, then all services with the specified topic are
returned. If \fIservice\fR is non-empty and \fItopic\fR is, all topics
for a given service are returned. If both are non-empty, if that
service-topic pair currently exists, it is returned; otherwise, an
empty string is returned.
.TP
\fBdde eval\fR ?\fB\-async\fR? \fItopic cmd \fR?\fIarg arg ...\fR?
.
\fBdde eval\fR evaluates a command and its arguments using the interpreter
specified by \fItopic\fR. The DDE service must be the \fBTclEval\fR
service.  The \fB\-async\fR option requests asynchronous invocation.  The
command returns an error message if the script did not run, unless the
\fB\-async\fR flag was used, in which case the command returns immediately
with no error.  This command can be used to replace send on Windows.
.SH "DDE AND TCL"

.SH EXAMPLE
This asks Internet Explorer (which must already be running) to go to a
particularly important website:
.CS
package require dde
\fBdde execute\fR iexplore WWW_OpenURL http://www.tcl.tk/
.CE

.SH "SEE ALSO"
tk(n), winfo(n), send(n)

.SH KEYWORDS
application, dde, name, remote execution

'\"
'\" Copyright (c) 2003 Donal K. Fellows
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
'\" RCS: @(#) $Id: dict.n,v 1.13 2007/10/24 14:29:38 dkf Exp $
'\"
.so man.macros
.TH dict n 8.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
dict \- Manipulate dictionaries

   }
}
# Another way to iterate and pick out names...
foreach id [\fBdict keys\fR $employeeInfo] {
   puts "Hello, [\fBdict get\fR $employeeInfo $id forenames]!"
}
.CE
.PP
A localizable version of \fBstring toupper\fR:
.CS
# Set up the basic C locale
set capital [\fBdict create\fR C [\fBdict create\fR]]
foreach c [split {abcdefghijklmnopqrstuvwxyz} ""] {
   \fBdict set\fR capital C $c [string toupper $c]
}

# English locales can luckily share the "C" locale
\fBdict set\fR capital en [\fBdict get\fR $capital C]
\fBdict set\fR capital en_US [\fBdict get\fR $capital C]
\fBdict set\fR capital en_GB [\fBdict get\fR $capital C]

# ... and so on for other supported languages ...

# Now get the mapping for the current locale and use it.
set upperCaseMap [\fBdict get\fR $capital $env(LANG)]
set upperCase [string map $upperCaseMap $string]
.CE

.SH "SEE ALSO"
append(n), array(n), foreach(n), incr(n), list(n), lappend(n), set(n)

.SH KEYWORDS
dictionary, create, update, lookup, iterate, filter

'\"
'\" Copyright (c) 1998 by Scriptics Corporation.
'\" 
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: encoding.n,v 1.11 2007/10/26 12:25:06 dkf Exp $
'\" 
.so man.macros
.TH encoding n "8.1" Tcl "Tcl Built-In Commands"
.BS
.SH NAME
encoding \- Manipulate encodings
.SH SYNOPSIS

that maps to the 00 page in Unicode.  The resulting Tcl strings will
not contain the expected Japanese characters.  Instead, they will
contain a sequence of Latin-1 characters that correspond to the bytes
of the original string.  The \fBencoding\fR command can be used to
convert this string to the expected Japanese Unicode characters.  For
example,
.CS
set s [\fBencoding convertfrom\fR euc-jp "\exA4\exCF"]
.CE
would return the Unicode string
.QW "\eu306F" ,
which is the Hiragana letter HA.

.SH "SEE ALSO"
fconfigure(n), Tcl_GetEncoding(3)

.SH KEYWORDS
encoding

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: eof.n,v 1.7 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH eof n 7.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
eof \- Check for end of file condition on channel

    if {[\fBeof\fR $f]} {
        close $f
        break
    }
    puts "Read record: $record"
}
.CE

.SH "SEE ALSO"
file(n), open(n), close(n), fblocked(n), Tcl_StandardChannels(3)

.SH KEYWORDS
channel, end of file

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\" Copyright (c) 2006 Donal K. Fellows.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: exec.n,v 1.18 2007/10/25 14:07:32 dkf Exp $
'\" 
.so man.macros
.TH exec n 8.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
exec \- Invoke subprocesses

Marks the end of switches.  The argument following this one will
be treated as the first \fIarg\fR even if it starts with a \fB\-\fR.
.PP
If an \fIarg\fR (or pair of \fIarg\fRs) has one of the forms
described below then it is used by \fBexec\fR to control the
flow of input and output among the subprocess(es).
Such arguments will not be passed to the subprocess(es).  In forms
such as
.QW "< \fIfileName\fR" ,
\fIfileName\fR may either be in a separate argument from
.QW <
or in the same argument with no intervening space (i.e.
.QW <\fIfileName\fR ).
.TP 15
|
Separates distinct commands in the pipeline.  The standard output
of the preceding command will be piped into the standard input
of the next command.
.TP 15
|&

all commands are redirected to \fIfileId\fR's file.
The file must have been opened for writing.
.PP
If standard output has not been redirected then the \fBexec\fR
command returns the standard output from the last command
in the pipeline,
.VS 8.5
unless
.QW 2>@1
was specified, in which case standard error is included as well.
.VE 8.5
If any of the commands in the pipeline exit abnormally or
are killed or suspended, then \fBexec\fR will return an error
and the error message will include the pipeline's output followed by
error messages describing the abnormal terminations; the
\fB-errorcode\fR return option will contain additional information
about the last abnormal termination encountered.

is a newline then that character is normally deleted
from the result or error message.
This is consistent with other Tcl return values, which don't
normally end with newlines.
However, if \fB\-keepnewline\fR is specified then the trailing
newline is retained.
.PP
If standard input isn't redirected with
.QW < ,
.QW <<
or
.QW <@
then the standard input for the first command in the
pipeline is taken from the application's current standard input.
.PP
If the last \fIarg\fR is
.QW &
then the pipeline will be executed in background.
In this case the \fBexec\fR command will return a list whose
elements are the process identifiers for all of the subprocesses
in the pipeline.
The standard output from the last command in the pipeline will
go to the application's standard output if it hasn't been
redirected, and error output from all of
the commands in the pipeline will go to the application's
standard error file unless redirected.
.PP
The first word in each command is taken as the command name;
tilde-substitution is performed on it, and if the result contains
no slashes then the directories
in the PATH environment variable are searched for
an executable by the given name.
If the name contains a slash then it must refer to an executable
reachable from the current directory. No
.QW glob
expansion or other shell-like substitutions
are performed on the arguments to commands.
.SH "PORTABILITY ISSUES"
.TP
\fBWindows\fR (all versions)
.
Reading from or writing to a socket, using the
.QW \fB@\0\fIfileId\fR
notation, does not work.  When reading from a socket, a 16-bit DOS
application will hang and a 32-bit application will return immediately with
end-of-file.  When either type of application writes to a socket, the
information is instead sent to the console, if one is present, or is
discarded.
.RS
.PP

backslashes only in paths.  Any arguments to an application that specify a
path name with forward slashes will not automatically be converted to use
the backslash character.  If an argument contains forward slashes as the
path separator, it may or may not be recognized as a path name, depending on
the program.  
.PP
Additionally, when calling a 16-bit DOS or Windows 3.X application, all path
names must use the short, cryptic, path format (e.g., using
.QW applba~1.def
instead of
.QW applbakery.default ),
which can be obtained with the
\fBfile attributes $fileName -shortname\fR command.
.PP
Two or more forward or backward slashes in a row in a path refer to a
network path.  For example, a simple concatenation of the root directory
\fBc:/\fR with a subdirectory \fB/windows/system\fR will yield
\fBc://windows/system\fR (two slashes together), which refers to the mount
point called \fBsystem\fR on the machine called \fBwindows\fR (and the

The Windows NT 16-bit system directory.
.IP \(bu
The Windows NT home directory.
.IP \(bu
The directories listed in the path.
.PP
In order to execute shell built-in commands like \fBdir\fR and \fBcopy\fR,
the caller must prepend the desired command with
.QW "\fBcmd.exe /c\0\fR"
because built-in commands are not implemented using executables.
.RE
.TP
\fBWindows 9x\fR
.
When attempting to execute an application, \fBexec\fR first searches for
the name as it was specified.  Then, in order, \fB.com\fR, \fB.exe\fR, and

The Windows 9x system directory.
.IP \(bu
The Windows 9x home directory.
.IP \(bu
The directories listed in the path.
.PP
In order to execute shell built-in commands like \fBdir\fR and \fBcopy\fR,
the caller must prepend the desired command with
.QW "\fBcommand.com /c\0\fR"
because built-in commands are not implemented using executables.
.PP
Once a 16-bit DOS application has read standard input from a console and 
then quit, all subsequently run 16-bit DOS applications will see the 
standard input as already closed.  32-bit applications do not have this
problem and will run correctly, even after a 16-bit DOS application thinks 
that standard input is closed.  There is no known workaround for this bug
at this time.
.PP
Redirection between the \fBNUL:\fR device and a 16-bit application does not
always work.  When redirecting from \fBNUL:\fR, some applications may hang,
others will get an infinite stream of
.QW 0x01
bytes, and some will actually
correctly get an immediate end-of-file; the behavior seems to depend upon 
something compiled into the application itself.  When redirecting greater than
4K or so to \fBNUL:\fR, some applications will hang.  The above problems do not
happen with 32-bit applications.  
.PP
All DOS 16-bit applications are run synchronously.  All standard input from
a pipe to a 16-bit DOS application is collected into a temporary file; the

same name and be in the path. It can then happen that typing a command
at the DOS prompt finds \fIa different program\fR than the same
command run via \fBexec\fR. This is because of the (documented)
differences in behaviour between \fBexec\fR and DOS batch files.
.PP
When in doubt, use the command \fBauto_execok\fR: it will return the
complete path to the program as seen by the \fBexec\fR command.  This
applies especially when you want to run
.QW "internal"
commands like \fIdir\fR from a Tcl script (if you just want to list
filenames, use the \fBglob\fR command.)  To do that, use this:
.CS
\fBexec\fR {*}[auto_execok dir] *.tcl
.CE
.SH "SEE ALSO"
error(n), open(n)
.SH KEYWORDS
execute, pipeline, redirection, subprocess

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-2000 Sun Microsystems, Inc.
'\" Copyright (c) 2005 by Kevin B. Kenny <[email protected]>. All rights reserved
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: expr.n,v 1.26 2007/10/25 09:35:14 dkf Exp $
'\" 
.so man.macros
.TH expr n 8.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
expr \- Evaluate an expression

.PP
For some examples of simple expressions, suppose the variable
\fBa\fR has the value 3 and
the variable \fBb\fR has the value 6.
Then the command on the left side of each of the lines below
will produce the value on the right side of the line:
.CS
.ta 3.5i
\fBexpr\fR 3.1 + $a	\fB\(-> \fI6.1\fR
\fBexpr\fR 2 + "$a.$b"	\fB\(-> \fI5.6\fR
\fBexpr\fR 4*[llength "6 2"]	\fB\(-> \fI8\fR
\fBexpr\fR {{word one} < "word $a"}	\fB\(-> \fI0\fR
.CE
.SS OPERATORS
.PP
The valid operators are listed below, grouped in decreasing order
of precedence:
.TP 20
\fB\-\0\0+\0\0~\0\0!\fR

All of the binary operators group left-to-right within the same
precedence level.  For example, the command
.CS
\fBexpr\fR {4*2 < 7}
.CE
returns 0.
.PP
The \fB&&\fR, \fB||\fR, and \fB?:\fR operators have
.QW "lazy evaluation" ,
just as in C, which means that operands are not evaluated if they are
not needed to determine the outcome.  For example, in the command
.CS
\fBexpr {$v ? [a] : [b]}\fR
.CE
only one of \fB[a]\fR or \fB[b]\fR will actually be evaluated,
depending on the value of \fB$v\fR.  Note, however, that this is
only true if the entire expression is enclosed in braces;  otherwise

\fBexpr\fR {5 / 4}
.CE
returns 1, while
.CS
\fBexpr\fR {5 / 4.0}
\fBexpr\fR {5 / ( [string length "abcd"] + 0.0 )}
.CE
both return 1.25. Floating-point values are always returned with a
.QW \fB.\fR
or an \fBe\fR so that they will not look like integer values.  For
example,
.CS
\fBexpr\fR {20.0/5.0}
.CE
returns \fB4.0\fR, not \fB4\fR.
.SS "STRING OPERATIONS"

the bytecode compiler must emit
additional instructions to handle this situation.
The most expensive code is required for
unbraced expressions that contain command substitutions.
These expressions must be implemented by generating new code
each time the expression is executed.
.SH EXAMPLES
Define a procedure that computes an
.QW "interesting"
mathematical function:
.CS
proc tcl::mathfunc::calc {x y} {
    \fBexpr\fR { ($x**2 - $y**2) / exp($x**2 + $y**2) }
}
.CE
.PP
Convert polar coordinates into cartesian coordinates:

}]
.CE
.PP
Generate a random integer in the range 0..99 inclusive:
.CS
set randNum [\fBexpr\fR { int(100 * rand()) }]
.CE

.SH "SEE ALSO"
array(n), for(n), if(n), mathfunc(n), namespace(n), proc(n), string(n),
Tcl(n), while(n)
.SH KEYWORDS
arithmetic, boolean, compare, expression, fuzzy comparison

.SH COPYRIGHT
.nf
Copyright \(co 1993 The Regents of the University of California.

Copyright \(co 1994-2000 Sun Microsystems Incorporated.
Copyright \(co 2005 by Kevin B. Kenny. All rights reserved.
.fi

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1997 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: fcopy.n,v 1.13 2007/10/25 14:07:32 dkf Exp $
'\" 
.so man.macros
.TH fcopy n 8.0 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
fcopy \- Copy data from one channel to another

and the command callback is \fInot\fR made.
If \fIinchan\fR is closed,
then all data already queued for \fIoutchan\fR is written out.
.PP
Note that \fIinchan\fR can become readable during a background copy.
You should turn off any \fBfileevent\fR handlers during a background
copy so those handlers do not interfere with the copy.
Any I/O attempted by a \fBfileevent\fR handler will get a
.QW "channel busy"
error.
.PP
\fBFcopy\fR translates end-of-line sequences in \fIinchan\fR and \fIoutchan\fR
according to the \fB\-translation\fR option
for these channels.
See the manual entry for \fBfconfigure\fR for details on the
\fB\-translation\fR option.
The translations mean that the number of bytes read from \fIinchan\fR
can be different than the number of bytes written to \fIoutchan\fR.
Only the number of bytes written to \fIoutchan\fR is reported,
either as the return value of a synchronous \fBfcopy\fR or
as the argument to the callback for an asynchronous \fBfcopy\fR.
.PP
\fBFcopy\fR obeys the encodings and character translations configured
for the channels. This
means that the incoming characters are converted internally first
UTF-8 and then into the encoding of the channel \fBfcopy\fR writes
to. See the manual entry for \fBfconfigure\fR for details on the
\fB\-encoding\fR and \fB\-translation\fR options. No conversion is
done if both channels are set to encoding
.QW "binary"
and have matching translations. If only the output channel is set to encoding
.QW "binary"
the system will write the internal UTF-8 representation of the incoming
characters. If only the input channel is set to encoding
.QW "binary"
the system will assume that the incoming bytes are valid UTF-8 characters and
convert them according to the output encoding. The behaviour of the system for
bytes which are not valid UTF-8 characters is undefined in this case.

.SH EXAMPLES
.PP
The first example transfers the contents of one channel exactly to
another. Note that when copying one file to another, it is better to
use \fBfile copy\fR which also copies file metadata (e.g. the file
access permissions) where possible.
.CS

set out [socket $server $port]
set chunk 1024
set total 0
\fBfcopy\fR $in $out -size $chunk \\
        -command [list CopyMore $in $out $chunk]
vwait done
.CE

.SH "SEE ALSO"
eof(n), fblocked(n), fconfigure(n), file(n)

.SH KEYWORDS
blocking, channel, end of line, end of file, nonblocking, read, translation

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: file.n,v 1.46 2007/10/25 14:07:32 dkf Exp $
'\" 
.so man.macros
.TH file n 8.3 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
file \- Manipulate file names and attributes

.RS
This subcommand returns or sets platform specific values associated
with a file. The first form returns a list of the platform specific
flags and their values. The second form returns the value for the
specific option. The third form sets one or more of the values. The
values are as follows:
.PP
On Unix, \fB\-group\fR gets or sets the group name for the file. A group id
can be given to the command, but it returns a group name. \fB\-owner\fR gets
or sets the user name of the owner of the file. The command returns the
owner name, but the numerical id can be passed when setting the
owner. \fB\-permissions\fR sets or retrieves the octal code that chmod(1)
uses.  This command does also has limited support for setting using the
symbolic attributes for chmod(1), of the form [ugo]?[[+\-=][rwxst],[...]],
where multiple symbolic attributes can be separated by commas (example:
\fBu+s,go\-rw\fR add sticky bit for user, remove read and write
permissions for group and other).  A simplified \fBls\fR style string,
of the form rwxrwxrwx (must be 9 characters), is also supported
(example: \fBrwxr\-xr\-t\fR is equivalent to 01755).
On versions of Unix supporting file flags, \fB\-readonly\fR gives the
value or sets or clears the readonly attribute of the file,
i.e. the user immutable flag \fBuchg\fR to chflags(1).
.PP
On Windows, \fB\-archive\fR gives the value or sets or clears the
archive attribute of the file. \fB\-hidden\fR gives the value or sets
or clears the hidden attribute of the file. \fB\-longname\fR will
expand each path element to its long version. This attribute cannot be
set. \fB\-readonly\fR gives the value or sets or clears the readonly
attribute of the file. \fB\-shortname\fR gives a string where every
path element is replaced with its short (8.3) version of the
name. This attribute cannot be set. \fB\-system\fR gives or sets or
clears the value of the system attribute of the file.
.PP
On Mac OS X and Darwin, \fB\-creator\fR gives or sets the
Finder creator type of the file. \fB\-hidden\fR gives or sets or clears
the hidden attribute of the file. \fB\-readonly\fR gives or sets or
clears the readonly attribute of the file. \fB\-rsrclength\fR gives
the length of the resource fork of the file, this attribute can only be
set to the value 0, which results in the resource fork being stripped
off the file.
.RE
.TP
\fBfile channels ?\fIpattern\fR?
.

argument.  Non-empty directories will be removed only if the
\fB\-force\fR option is specified.  When operating on symbolic links,
the links themselves will be deleted, not the objects they point to.
Trying to delete a non-existent file is not considered an error.
Trying to delete a read-only file will cause the file to be deleted,
even if the \fB\-force\fR flags is not specified.  If the \fB\-force\fR
option is specified on a directory, Tcl will attempt both to change
permissions and move the current directory
.QW pwd
out of the given path
if that is necessary to allow the deletion to proceed.  Arguments are
processed in the order specified, halting at the first error, if any.
A \fB\-\|\-\fR marks the end of switches; the argument following the
\fB\-\|\-\fR will be treated as a \fIpathname\fR even if it starts with
a \fB\-\fR.
.TP
\fBfile dirname \fIname\fR
Returns a name comprised of all of the path components in \fIname\fR
excluding the last element.  If \fIname\fR is a relative file name and
only contains one path element, then returns
.QW \fB.\fR .
If \fIname\fR refers to a root directory, then the root directory is
returned.  For example,
.RS
.CS
\fBfile dirname c:/\fR
.CE
returns \fBc:/\fR. 
.PP
Note that tilde substitution will only be

returns \fB/foo/bar\fR.
.PP
Note that any of the names can contain separators, and that the result
is always canonical for the current platform: \fB/\fR for Unix and
Windows.
.RE
.TP
\fBfile link ?\fI\-linktype\fR? \fIlinkName\fR ?\fItarget\fR?
.
If only one argument is given, that argument is assumed to be
\fIlinkName\fR, and this command returns the value of the link given by
\fIlinkName\fR (i.e. the name of the file it points to).  If
\fIlinkName\fR isn't a link or its value cannot be read (as, for example,
seems to be the case with hard links, which look just like ordinary
files), then an error is returned.
.
If 2 arguments are given, then these are assumed to be \fIlinkName\fR
and \fItarget\fR. If \fIlinkName\fR already exists, or if \fItarget\fR
doesn't exist, an error will be returned.  Otherwise, Tcl creates a new
link called \fIlinkName\fR which points to the existing filesystem
object at \fItarget\fR (which is also the returned value), where the
type of the link is platform-specific (on Unix a symbolic link will be
the default).  This is useful for the case where the user wishes to
create a link in a cross-platform way, and doesn't care what type of
link is created.
.
If the user wishes to make a link of a specific type only, (and signal an
error if for some reason that is not possible), then the optional
\fI\-linktype\fR argument should be given.  Accepted values for
\fI\-linktype\fR are
.QW "\-symbolic"
and
.QW "\-hard" .
.
On Unix, symbolic links can be made to relative paths, and those paths
must be relative to the actual \fIlinkName\fR's location (not to the
cwd), but on all other platforms where relative links are not supported,
target paths will always be converted to absolute, normalized form
before the link is created (and therefore relative paths are interpreted
as relative to the cwd).  Furthermore,
.QW "~user"
paths are always expanded
to absolute form.  When creating links on filesystems that either do not
support any links, or do not support the specific type requested, an
error message will be returned.  In particular Windows 95, 98 and ME do
not support any links at present, but most Unix platforms support both
symbolic and hard links (the latter for files only) and Windows
NT/2000/XP (on NTFS drives) support symbolic
directory links and hard file links.

.TP
\fBfile normalize \fIname\fR
.
.RS
Returns a unique normalized path representation for the file-system
object (file, directory, link, etc), whose string value can be used as a
unique identifier for it.  A normalized path is an absolute path which has
all
.QW ../ ,
.QW ./
removed.  Also it is one which is in the
.QW standard
format for the native platform.  On Unix, this means the segments
leading up to the path must be free of symbolic links/aliases (but the
very last path component may be a symbolic link), and on Windows it also
means we want the long form with that form's case-dependence (which
gives us a unique, case-dependent path).  The one exception concerning the
last link in the path is necessary, because Tcl or the user may wish to
operate on the actual symbolic link itself (for example \fBfile
delete\fR, \fBfile rename\fR, \fBfile copy\fR are defined to operate
on symbolic links, not on the things that they point to).
.RE
.TP
\fBfile owned \fIname\fR 
.
Returns \fB1\fR if file \fIname\fR is owned by the current user, \fB0\fR
otherwise.
.TP

switches; the argument following the \fB\-\|\-\fR will be treated as a
\fIsource\fR even if it starts with a \fB\-\fR.
.RE
.TP
\fBfile rootname \fIname\fR
.
Returns all of the characters in \fIname\fR up to but not including the
last
.QW .
character in the last component of name.  If the last
component of \fIname\fR doesn't contain a dot, then returns \fIname\fR.
.TP
\fBfile separator\fR ?\fIname\fR?
.
If no argument is given, returns the character which is used to separate 
path segments for native files on this platform.  If a path is given,
the filesystem responsible for that path is asked to return its

\fBfile system \fIname\fR
.
Returns a list of one or two elements, the first of which is the name of
the filesystem to use for the file, and the second, if given, an
arbitrary string representing the filesystem-specific nature or type of
the location within that filesystem.  If a filesystem only supports one
type of file, the second element may not be supplied.  For example the
native files have a first element
.QW native ,
and a second element which
when given is a platform-specific type name for the file's system
(e.g.
.QW NTFS ,
.QW FAT ,
on Windows).  A generic virtual file system might return the list
.QW "vfs ftp"
to represent a file on a remote ftp site mounted as a virtual
filesystem through an extension called
.QW vfs .
If the file does not belong to any filesystem, an error is generated.
.TP
\fBfile tail \fIname\fR
.
Returns all of the characters in the last filesystem component of
\fIname\fR.  Any trailing directory separator in \fIname\fR is ignored.
If \fIname\fR contains no separators then returns \fIname\fR.  So, 
\fBfile tail a/b\fR, \fBfile tail a/b/\fR and \fBfile tail b\fR all
return \fBb\fR.
.TP
\fBfile type \fIname\fR
.
Returns a string giving the type of file \fIname\fR, which will be one of
\fBfile\fR, \fBdirectory\fR, \fBcharacterSpecial\fR, \fBblockSpecial\fR,
\fBfifo\fR, \fBlink\fR, or \fBsocket\fR.
.TP
\fBfile volumes\fR
. 
Returns the absolute paths to the volumes mounted on the system, as a proper
Tcl list. Without any virtual filesystems mounted as root volumes, on UNIX,
the command will always return
.QW "/" ,
since all filesystems are locally mounted. On Windows, it will return a list
of the available local drives (e.g.
.QW "a:/ c:/" ).
If any virtual filesystem has mounted additional volumes, they will be in the
returned list.
.TP
\fBfile writable \fIname\fR
.
Returns \fB1\fR if file \fIname\fR is writable by the current user,
\fB0\fR otherwise.
.SH "PORTABILITY ISSUES"
.TP

Rename a file and leave a symbolic link pointing from the old location
to the new place:
.CS
set oldName foobar.txt
set newName foo/bar.txt
# Make sure that where we're going to move to exists...
if {![\fBfile isdirectory\fR [\fBfile dirname\fR $newName]]} {
    \fBfile mkdir\fR [\fBfile dirname\fR $newName]
}
\fBfile rename\fR $oldName $newName
\fBfile link\fR -symbolic $oldName $newName
.CE

.SH "SEE ALSO"
chan(n), close(n), eof(n), fblocked(n), filename(n), flush(n), gets(n),
open(n), seek(n), tell(n)
.SH KEYWORDS
attributes, copy files, delete files, directory, file, move files, name, rename files, stat

'\"
'\" Copyright (c) 1994 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: fileevent.n,v 1.10 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH fileevent n 7.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
fileevent \- Execute a script when a channel becomes readable or writable

is evaluated whenever the channel becomes readable or writable.  File event
handlers are most commonly used to allow data to be received from another
process on an event-driven basis, so that the receiver can continue to
interact with the user while waiting for the data to arrive.  If an
application invokes \fBgets\fR or \fBread\fR on a blocking channel when
there is no input data available, the process will block; until the input
data arrives, it will not be able to service other events, so it will
appear to the user to
.QW "freeze up" .
With \fBfileevent\fR, the process can
tell when data is present and only invoke \fBgets\fR or \fBread\fR when
they won't block.
.PP
The \fIchannelId\fR argument to \fBfileevent\fR refers to an open
channel such as a Tcl standard channel (\fBstdin\fR, \fBstdout\fR,
or \fBstderr\fR), the return value from an invocation of \fBopen\fR
or \fBsocket\fR, or the result of a channel creation command provided

    if {![eof $chan]} {
        puts [gets $chan]
    }
}

\fBfileevent\fR $chan readable [list GetData $chan]
.CE

.SH CREDITS
.PP
\fBfileevent\fR is based on the \fBaddinput\fR command created
by Mark Diekhans.

.SH "SEE ALSO"
fconfigure(n), gets(n), interp(n), puts(n), read(n), Tcl_StandardChannels(3)

.SH KEYWORDS
asynchronous I/O, blocking, channel, event handler, nonblocking, readable,
script, writable.

'\"
'\" Copyright (c) 1995-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: filename.n,v 1.16 2007/10/25 14:07:32 dkf Exp $
'\" 
.so man.macros
.TH filename n 7.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
filename \- File name conventions supported by Tcl commands

Tcl attempts to interpret that part of the path or otherwise access the
file.  The behaviour of these paths when not trying to interpret them is
the same as on Unix.  File names that have a tilde without a user name
will be correctly substituted using the \fB$HOME\fR environment
variable, just like for Unix.
.SH "PORTABILITY ISSUES"
.PP
Not all file systems are case sensitive, so scripts should avoid code that
depends on the case of characters in a file name. In addition, the character
sets allowed on different devices may differ, so scripts should choose file
names that do not contain special characters like: \fB<>:?"/\e|\fR.
.\"" Reset emacs highlighting
The safest approach is to use names consisting of alphanumeric characters
only. Care should be taken with filenames which contain spaces (common on

Windows systems) and filenames where the backslash is the directory separator
(Windows native path names). Also Windows 3.1 only supports file names with a
root of no more than 8 characters and an extension of no more than 3
characters.
.PP
On Windows platforms there are file and path length restrictions. Complete
paths or filenames longer than about 260 characters will lead to errors in
most file operations.
.PP
Another Windows peculiarity is that any number of trailing dots
.QW "."
in filenames are totally ignored, so, for example, attempts to create a file
or directory with a name
.QW "foo."
will result in the creation of a file or directory with name
.QW "foo" .
This fact is reflected in the results of
.QW \fBfile normalize\fR .
Furthermore, a file name consisting only of dots
.QW "........."
or dots with trailing characters
.QW ".....abc"
is illegal.
.SH KEYWORDS
current directory, absolute file name, relative file name,
volume-relative file name, portability
.SH "SEE ALSO"
file(n), glob(n)

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1997 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: for.n,v 1.6 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH for n "" Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
for \- `For' loop
.SH SYNOPSIS
\fBfor \fIstart test next body\fR
.BE

.SH DESCRIPTION
.PP
\fBFor\fR is a looping command, similar in structure to the C

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: format.n,v 1.16 2007/10/25 14:07:32 dkf Exp $
'\" 
.so man.macros
.TH format n 8.1 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
format \- Format a string in the style of sprintf

a set of flags, a minimum field width, a precision, a size modifier,
and a conversion character.
Any of these fields may be omitted except for the conversion character.
The fields that are present must appear in the order given above.
The paragraphs below discuss each of these fields in turn.
.PP
If the \fB%\fR is followed by a decimal number and a \fB$\fR, as in
.QW \fB%2$d\fR ,
then the value to convert is not taken from the next sequential argument.
Instead, it is taken from the argument indicated by the number,
where 1 corresponds to the first \fIarg\fR.
If the conversion specifier requires multiple arguments because
of \fB*\fR characters in the specifier then
successive arguments are used, starting with the argument
given by the number.
This follows the XPG3 conventions for positional specifiers.

Convert integer to signed decimal string (equivalent to \fBd\fR).
.TP 10
\fBo\fR
Convert integer to unsigned octal string.
.TP 10
\fBx\fR or \fBX\fR
Convert integer to unsigned hexadecimal string, using digits
.QW 0123456789abcdef
for \fBx\fR and
.QW 0123456789ABCDEF
for \fBX\fR).
.TP 10
\fBc\fR
Convert integer to the Unicode character it represents.
.TP 10
\fBs\fR
No conversion; just insert string.
.TP 10
\fBf\fR
Convert number to signed decimal string of 
the form \fIxx.yyy\fR, where the number of \fIy\fR's is determined by 
the precision (default: 6).
If the precision is 0 then no decimal point is output.
.TP 10
\fBe\fR or \fBE\fR
Convert number to scientific notation in the 
form
.QW "\fIx.yyy\fBe\(+-\fIzz\fR" ,
where the number of \fIy\fR's is determined by the precision (default: 6).
If the precision is 0 then no decimal point is output.
If the \fBE\fR form is used then \fBE\fR is 
printed instead of \fBe\fR.
.TP 10
\fBg\fR or \fBG\fR
If the exponent is less than \-4 or greater than or equal to the 
precision, then convert number as for \fB%e\fR or 

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: glob.n,v 1.19 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH glob n 8.3 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
glob \- Return names of files that match patterns
.SH SYNOPSIS
\fBglob \fR?\fIswitches\fR? \fIpattern \fR?\fIpattern ...\fR?
.BE

.SH DESCRIPTION
.PP
This command performs file name
.QW globbing
in a fashion similar to
the csh shell.  It returns a list of the files whose names match any
of the \fIpattern\fR arguments.  No particular order is guaranteed
in the list, so if a sorted list is required the caller should use 
\fBlsort\fR.
.LP
If the initial arguments to \fBglob\fR start with \fB\-\fR then
they are treated as switches.  The following switches are

The following are equivalent:
.RS
.CS
\fBglob \-type d *\fR
\fBglob */\fR
.CE
.RE
except that the first case doesn't return the trailing
.QW /
and is more platform independent.
.RE
.TP
\fB\-\|\-\fR
Marks the end of switches.  The argument following this one will
be treated as a \fIpattern\fR even if it starts with a \fB\-\fR.
.PP
The \fIpattern\fR arguments may contain any of the following

.TP 10
\fB\e\fIx\fR
Matches the character \fIx\fR.
.TP 10
\fB{\fIa\fB,\fIb\fB,\fI...\fR}
Matches any of the strings \fIa\fR, \fIb\fR, etc.
.LP
On Unix, as with csh, a
.QW .
at the beginning of a file's name or just after a
.QW /
must be matched explicitly or with a {} construct, unless the
.QW "-types hidden"
flag is given (since
.QW .
at the beginning 
of a file's name indicates that it is hidden).  On other platforms,
files beginning with a
.QW .
are handled no differently to any others,
except the special directories
.QW .
and
.QW ..
which must be matched explicitly (this is to avoid a recursive pattern like
.QW "glob -join * * * *"
from recursing up the directory hierarchy as well as down). In addition, all
.QW /
characters must be matched explicitly.
.LP
If the first character in a \fIpattern\fR is
.QW ~
then it refers to the home directory for the user whose name follows the
.QW ~ .
If the
.QW ~
is followed immediately by
.QW /
then the value of the HOME environment variable is used.
.LP
The \fBglob\fR command differs from csh globbing in two ways.
First, it does not sort its result list (use the \fBlsort\fR
command if you want the list sorted).
Second, \fBglob\fR only returns the names of files that actually
exist;  in csh no check for existence is made unless a pattern
contains a ?, *, or [] construct.
.LP
When the \fBglob\fR command returns relative paths whose filenames
start with a tilde
.QW ~
(for example through \fBglob *\fR or 
\fBglob -tails\fR, the returned list will not quote the tilde with
.QW ./ .
This means care must be taken if those names are later to
be used with \fBfile join\fR, to avoid them being interpreted as
absolute paths pointing to a given user's home directory.
.SH "PORTABILITY ISSUES"
.TP
\fBWindows\fR
.
For Windows UNC names, the servername and sharename components of the path
may not contain ?, *, or [] constructs.  On Windows NT, if \fIpattern\fR is
of the form
.QW \fB~\fIusername\fB@\fIdomain\fR
it refers to the home
directory of the user whose account information resides on the specified NT
domain server.  Otherwise, user account information is obtained from
the local computer.  On Windows 95 and 98, \fBglob\fR accepts patterns
like
.QW .../
and
.QW ..../
for successively higher up parent directories.
.RS
.PP

Since the backslash character has a special meaning to the glob 
command, glob patterns containing Windows style path separators need 
special care. The pattern \fIC:\e\efoo\e\e*\fR is interpreted as 
\fIC:\efoo\e*\fR where \fI\ef\fR will match the single character \fIf\fR 
and \fI\e*\fR will match the single character \fI*\fR and will not be 
interpreted as a wildcard character. One solution to this problem is 
to use the Unix style forward slash as a path separator. Windows style 

.CE
.PP
Find all subdirectories of the current directory:
.CS
\fBglob\fR \-type d *
.CE
.PP
Find all files whose name contains an
.QW a ,
a
.QW b
or the sequence
.QW cde :
.CS
\fBglob\fR \-type f *{a,b,cde}*
.CE

.SH "SEE ALSO"
file(n)

.SH KEYWORDS
exist, file, glob, pattern

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1997 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: history.n,v 1.5 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH history n "" Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
history \- Manipulate the history list
.SH SYNOPSIS
\fBhistory \fR?\fIoption\fR? ?\fIarg arg ...\fR?
.BE

.SH DESCRIPTION
.PP
The \fBhistory\fR command performs one of several operations related to
recently-executed commands recorded in a history list.  Each of
these recorded commands is referred to as an
.QW event .
When specifying an event to the \fBhistory\fR command, the following
forms may be used:
.IP [1]
A number:  if positive, it refers to the event with
that number (all events are numbered starting at 1).  If the number
is negative, it selects an event relative to the current event
(\fB\-1\fR refers to the previous event, \fB\-2\fR to the one before that, and
so on).  Event \fB0\fR refers to the current event.

.SH "HISTORY REVISION"
.PP
Pre-8.0 Tcl had a complex history revision mechanism.
The current mechanism is more limited, and the old
history operations \fBsubstitute\fR and \fBwords\fR have been removed.
(As a consolation, the \fBclear\fR operation was added.)
.PP
The history option \fBredo\fR results in much simpler
.QW "history revision" .
When this option is invoked then the most recent event
is modified to eliminate the history command and replace it with
the result of the history command.
If you want to redo an event without modifying history, then use
the \fBevent\fR operation to retrieve some event,
and the \fBadd\fR operation to add it to history and execute it.

.SH KEYWORDS
event, history, record

'\"
'\" Copyright (c) 1995-1997 Sun Microsystems, Inc.
'\" Copyright (c) 1998-2000 by Ajuba Solutions.
'\" Copyright (c) 2004 ActiveState Corporation.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: http.n,v 1.26 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH "http" n 2.5 http "Tcl Bundled Packages"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
http \- Client-side implementation of the HTTP/1.0 protocol

flags and values that define the configuration:
.RS
.TP
\fB\-accept\fR \fImimetypes\fR
The Accept header of the request.  The default is */*, which means that
all types of documents are accepted.  Otherwise you can supply a 
comma-separated list of mime type patterns that you are
willing to receive.  For example,
.QW "image/gif, image/jpeg, text/*" .
.TP
\fB\-proxyhost\fR \fIhostname\fR
The name of the proxy host, if any.  If this value is the
empty string, the URL host is contacted directly.
.TP
\fB\-proxyport\fR \fInumber\fR
The proxy port number.

returned by specifying the empty string (\fB{}\fR), although
\fIiso8859-1\fR is recommended to restore similar behavior but without the
\fB::http::formatQuery\fR throwing an error processing non-latin-1
characters.
.TP
\fB\-useragent\fR \fIstring\fR
The value of the User-Agent header in the HTTP request.  The default
is
.QW "\fBTcl http client package 2.5\fR" .
.RE
.TP
\fB::http::geturl\fR \fIurl\fR ?\fIoptions\fR? 
The \fB::http::geturl\fR command is the main procedure in the package.
The \fB\-query\fR option causes a POST operation and
the \fB\-validate\fR option causes a HEAD operation;
otherwise, a GET operation is performed.  The \fB::http::geturl\fR command

set token [::http::geturl https://my.secure.site/]
.CE
.RE
.TP
\fB::http::unregister\fR \fIproto\fR
This procedure unregisters a protocol handler that was previously
registered via \fB::http::register\fR.

.SH "ERRORS"
The \fB::http::geturl\fR procedure will raise errors in the following cases:
invalid command line options,
an invalid URL,
a URL on a non-existent host,
or a URL at a bad port on an existing host.
These errors mean that it

These are described below.
.TP
ok
If the HTTP transaction completes entirely, then status will be \fBok\fR.
However, you should still check the \fB::http::code\fR value to get
the HTTP status.  The \fB::http::ncode\fR procedure provides just
the numeric error (e.g., 200, 404 or 500) while the \fB::http::code\fR
procedure returns a value like
.QW "HTTP 404 File not found" .
.TP
eof
If the server closes the socket without replying, then no error
is raised, but the status of the transaction will be \fBeof\fR.
.TP
error
The error message will also be stored in the \fBerror\fR status
array element, accessible via \fB::http::error\fR.
.PP
Another error possibility is that \fB::http::geturl\fR is unable to
write all the post query data to the server before the server
responds and closes the socket.
The error message is saved in the \fBposterror\fR status array
element and then  \fB::http::geturl\fR attempts to complete the
transaction.
If it can read the server's response
it will end up with an \fBok\fR status, otherwise it will have
an \fBeof\fR status.

.SH "STATE ARRAY"
The \fB::http::geturl\fR procedure returns a \fItoken\fR that can be used to
get to the state of the HTTP transaction in the form of a Tcl array.
Use this construct to create an easy-to-use array variable:
.CS
upvar #0 $token state
.CE

   return $token
}
proc httpCopyProgress {args} {
   puts -nonewline stderr .
   flush stderr
}
.CE

.SH "SEE ALSO"
safe(n), socket(n), safesock(n)

.SH KEYWORDS
security policy, socket

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: if.n,v 1.6 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH if n "" Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
if \- Execute scripts conditionally

if it is true then \fIbody1\fR is executed by passing it to the
Tcl interpreter.
Otherwise \fIexpr2\fR is evaluated as an expression and if it is true
then \fBbody2\fR is executed, and so on.
If none of the expressions evaluates to true then \fIbodyN\fR is
executed.
The \fBthen\fR and \fBelse\fR arguments are optional
.QW noise words
to make the command easier to read.
There may be any number of \fBelseif\fR clauses, including zero.
\fIBodyN\fR may also be omitted as long as \fBelse\fR is omitted too.
The return value from the command is the result of the body script
that was executed, or an empty string
if none of the expressions was non-zero and there was no \fIbodyN\fR.
.SH EXAMPLES
A simple conditional:

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1997 Sun Microsystems, Inc.
'\" Copyright (c) 1993-1997 Bell Labs Innovations for Lucent Technologies
'\" Copyright (c) 1998-2000 Ajuba Solutions
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: info.n,v 1.20 2007/10/25 14:07:32 dkf Exp $
'\" 
.so man.macros
.TH info n 8.4 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
info \- Return information about the state of the Tcl interpreter
.SH SYNOPSIS
\fBinfo \fIoption \fR?\fIarg arg ...\fR?
.BE

.SH DESCRIPTION
.PP
This command provides information about various internals of the Tcl
interpreter.
The legal \fIoption\fRs (which may be abbreviated) are:
.TP
\fBinfo args \fIprocname\fR
Returns a list containing the names of the arguments to procedure
\fIprocname\fR, in order.  \fIProcname\fR must be the name of a
Tcl command procedure.
.TP
\fBinfo body \fIprocname\fR

If \fInumber\fR is positive (> 0) then it selects a particular stack
level (1 refers to the top-most active command, i.e., \fBinfo frame\fR
itself, 2 to the command it was called from, and so on); otherwise it
gives a level relative to the current command (0 refers to the current
command, i.e., \fBinfo frame\fR itself, -1 to its caller, and so on).
.sp
This is similar to how \fBinfo level\fR works, except that this
subcommand reports all frames, like \fBsource\fRd scripts,
\fBeval\fRs, \fBuplevel\fRs, etc.
.sp
Note that for nested commands, like
.QW "foo [[bar [[x]]]]"
only
.QW "x"
will be seen by an \fBinfo frame\fR invoked within
.QW "x" .
This is the same as for \fBinfo level\fR and error stack traces.
.sp
The result dictionary may contain the keys listed below, with the
specified meanings for their values:
.RS
.TP
\fItype\fR
This entry is always present and describes the nature of the location

using a sequence of namespace names separated by double colons (\fB::\fR),
and may have pattern matching special characters
at the end to specify a set of variables in that namespace.
If \fIpattern\fR is a qualified name,
the resulting list of variable names
has each matching namespace variable qualified with the name
of its namespace.
Note that a currently-visible variable may not yet
.QW "exist"
if it has not
been set (e.g. a variable declared but not set by \fBvariable\fR).
.SH EXAMPLE
This command prints out a procedure suitable for saving in a Tcl
script:
.PP
.CS
proc printProc {procName} {

'\"
'\" Copyright (c) 1995-1996 Sun Microsystems, Inc.
'\" Copyright (c) 2004 Donal K. Fellows
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: interp.n,v 1.30 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH interp n 7.6 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
interp \- Create and manipulate Tcl interpreters

This command creates an alias between one slave and another (see the
\fBalias\fR slave command below for creating aliases between a slave
and its master).  In this command, either of the slave interpreters
may be anywhere in the hierarchy of interpreters under the interpreter
invoking the command.
\fISrcPath\fR and \fIsrcCmd\fR identify the source of the alias.
\fISrcPath\fR is a Tcl list whose elements select a particular
interpreter.  For example,
.QW "\fBa b\fR"
identifies an interpreter
\fBb\fR, which is a slave of interpreter \fBa\fR, which is a slave
of the invoking interpreter.  An empty list specifies the interpreter
invoking the command.  \fIsrcCmd\fR gives the name of a new
command, which will be created in the source interpreter.
\fITargetPath\fR and \fItargetCmd\fR specify a target interpreter
and command, and the \fIarg\fR arguments, if any, specify additional
arguments to \fItargetCmd\fR which are prepended to any arguments specified

When the source for an alias is invoked in the slave interpreter, the
usual Tcl substitutions are performed when parsing that command.
These substitutions are carried out in the source interpreter just
as they would be for any other command invoked in that interpreter.
The command procedure for the source command takes its arguments
and merges them with the \fItargetCmd\fR and \fIarg\fRs for the
alias to create a new array of arguments.  If the words
of \fIsrcCmd\fR were
.QW "\fIsrcCmd arg1 arg2 ... argN\fR" ,
the new set of words will be
.QW "\fItargetCmd arg arg ... arg arg1 arg2 ... argN\fR" ,
where \fItargetCmd\fR and \fIarg\fRs are the values supplied when the
alias was created.  \fITargetCmd\fR is then used to locate a command
procedure in the target interpreter, and that command procedure
is invoked with the new set of arguments.  An error occurs if
there is no command named \fItargetCmd\fR in the target interpreter.
No additional substitutions are performed on the words:  the
target command procedure is invoked directly, without

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: join.n,v 1.6 2007/10/25 09:25:27 dkf Exp $
'\" 
.so man.macros
.TH join n "" Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
join \- Create a string by joining together list elements
.SH SYNOPSIS
\fBjoin \fIlist \fR?\fIjoinString\fR?
.BE

.SH DESCRIPTION
.PP
The \fIlist\fR argument must be a valid Tcl list.
This command returns the string
formed by joining all of the elements of \fIlist\fR together with
\fIjoinString\fR separating each adjacent pair of elements.
The \fIjoinString\fR argument defaults to a space character.
.SH EXAMPLES
Making a comma-separated list:
.CS
.ta 2i
set data {1 2 3 4 5}
\fBjoin\fR $data ", "
	 \fB\(->\fI 1, 2, 3, 4, 5\fR
.CE
.PP
Using \fBjoin\fR to flatten a list by a single level:
.CS
.ta 2i
set data {1 {2 3} 4 {5 {6 7} 8}}
\fBjoin\fR $data
	 \fB\(->\fI 1 2 3 4 5 {6 7} 8\fR
.CE

.SH "SEE ALSO"
list(n), lappend(n), split(n)

.SH KEYWORDS
element, join, list, separator

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\" Copyright (c) 2001 Kevin B. Kenny.  All rights reserved.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: lappend.n,v 1.12 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH lappend n "" Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
lappend \- Append list elements onto a variable

and appends each of the \fIvalue\fR arguments to that list as a separate
element, with spaces between elements.
If \fIvarName\fR doesn't exist, it is created as a list with elements
given by the \fIvalue\fR arguments.
\fBLappend\fR is similar to \fBappend\fR except that the \fIvalue\fRs
are appended as list elements rather than raw text.
This command provides a relatively efficient way to build up
large lists.  For example,
.QW "\fBlappend a $b\fR"
is much more efficient than
.QW "\fBset a [concat $a [list $b]]\fR" ,
especially when \fB$a\fR is long.
.SH EXAMPLE
Using \fBlappend\fR to build up a list of numbers.
.CS
% set var 1
1
% \fBlappend\fR var 2
1 2

'\"
'\" Copyright (c) 1992-1999 Karl Lehenbauer & Mark Diekhans
'\" Copyright (c) 2004 Donal K. Fellows
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: lassign.n,v 1.2 2007/10/25 09:31:52 dkf Exp $
'\" 
.so man.macros
.TH lassign n 8.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
lassign \- Assign list elements to variables
.SH SYNOPSIS
\fBlassign \fIlist varName \fR?\fIvarName ...\fR?
.BE

.SH DESCRIPTION
.PP
This command treats the value \fIlist\fR as a list and assigns
successive elements from that list to the variables given by the
\fIvarName\fR arguments in order.  If there are more variable names
than list elements, the remaining variables are set to the empty
string.  If there are more list elements than variables, a list of
unassigned elements is returned.
.SH EXAMPLES
An illustration of how multiple assignment works, and what happens
when there are either too few or too many elements.
.CS
.ta 2.5i
lassign {a b c} x y z	\fB\(->\fI Empty return\fR
puts $x	\fB\(->\fI Prints "a"\fR
puts $y	\fB\(->\fI Prints "b"\fR
puts $z	\fB\(->\fI Prints "c"\fR

lassign {d e} x y z	\fB\(->\fI Empty return\fR
puts $x	\fB\(->\fI Prints "d"\fR
puts $y	\fB\(->\fI Prints "e"\fR
puts $z	\fB\(->\fI Prints ""\fR

lassign {f g h i} x y	\fB\(->\fI Returns "h i"\fR
puts $x	\fB\(->\fI Prints "f"\fR
puts $y	\fB\(->\fI Prints "g"\fR
.CE
.PP
The \fBlassign\fR command has other uses.  It can be used to create
the analogue of the
.QW shift
command in many shell languages like this:
.CS
set ::argv [lassign $::argv argumentToReadOff]
.CE
.SH "SEE ALSO"
lindex(n), list(n), lset(n), set(n)

.SH KEYWORDS
assign, element, list, multiple, set, variable

'\"
'\" Copyright (c) 1991-1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: library.n,v 1.19 2007/10/24 14:29:38 dkf Exp $
.so man.macros
.TH library n "8.0" Tcl "Tcl Built-In Commands"
.BS
.SH NAME
auto_execok, auto_import, auto_load, auto_mkindex, auto_mkindex_old, auto_qualify, auto_reset, tcl_findLibrary, parray, tcl_endOfWord, tcl_startOfNextWord, tcl_startOfPreviousWord, tcl_wordBreakAfter, tcl_wordBreakBefore \- standard library of Tcl procedures
.SH SYNOPSIS
.nf

\fBsource [file join [info library] init.tcl]\fR
.CE
If the library procedure \fBTcl_Init\fR is invoked from an application's
\fBTcl_AppInit\fR procedure, this happens automatically.
The code in \fBinit.tcl\fR will define the \fBunknown\fR procedure
and arrange for the other procedures to be loaded on-demand using
the auto-load mechanism defined below.

.SH "COMMAND PROCEDURES"
.PP
The following procedures are provided in the Tcl library:
.TP
\fBauto_execok \fIcmd\fR
Determines whether there is an executable file or shell builtin
by the name \fIcmd\fR.  If so, it returns a list of arguments to be

\fBAuto_mkindex_old\fR parses the Tcl scripts in a relatively
unsophisticated way:  if any line contains the word \fBproc\fR
as its first characters then it is assumed to be a procedure
definition and the next word of the line is taken as the
procedure's name.
Procedure definitions that don't appear in this way (e.g. they
have spaces before the \fBproc\fR) will not be indexed.  If your 
script contains
.QW dangerous
code, such as global initialization
code or procedure names with special characters like \fB$\fR,
\fB*\fR, \fB[\fR or \fB]\fR, you are safer using auto_mkindex_old.
.RE
.TP
\fBauto_reset\fR
Destroys all the information cached by \fBauto_execok\fR and
\fBauto_load\fR.  This information will be re-read from disk the next

.TP
\fBtcl_findLibrary \fIbasename version patch initScript enVarName varName\fR
This is a standard search procedure for use by extensions during
their initialization.  They call this procedure to look for their
script library in several standard directories.
The last component of the name of the library directory is 
normally \fIbasenameversion\fR
(e.g., tk8.0), but it might be
.QW library
when in the build hierarchies.
The \fIinitScript\fR file will be sourced into the interpreter
once it is found.  The directory in which this file is found is
stored into the global variable \fIvarName\fR.
If this variable is already defined (e.g., by C code during
application initialization) then no searching is done.
Otherwise the search looks in these directories:
the directory named by the environment variable \fIenVarName\fR;

.TP
\fBtcl_wordBreakBefore \fIstr start\fR
Returns the index of the first word boundary before the starting index
\fIstart\fR in the string \fIstr\fR.  Returns \-1 if there are no more
boundaries before the starting point in the given string.  The index
returned refers to the second character of the pair that comprises a
boundary.

.SH "VARIABLES"
.PP
The following global variables are defined or used by the procedures in
the Tcl library:
.TP
\fBauto_execs\fR
Used by \fBauto_execok\fR to record information about whether

assigned to the \fBtcl_library\fR variable and therefore returned by
the command \fBinfo library\fR).  If this variable isn't set then
a default value is used.
.TP
\fBenv(TCLLIBPATH)\fR
If set, then it must contain a valid Tcl list giving directories to
search during auto-load operations.  Directories must be specified in 
Tcl format, using
.QW /
as the path separator, regardless of platform.
This variable is only used when initializing the \fBauto_path\fR variable.
.TP
\fBtcl_nonwordchars\fR
This variable contains a regular expression that is used by routines
like \fBtcl_endOfWord\fR to identify whether a character is part of a
word or not.  If the pattern matches a character, the character is
considered to be a non-word character.  On Windows platforms, spaces,
tabs, and newlines are considered non-word characters.  Under Unix,
everything but numbers, letters and underscores are considered
non-word characters.
.TP
\fBtcl_wordchars\fR
This variable contains a regular expression that is used by routines
like \fBtcl_endOfWord\fR to identify whether a character is part of a
word or not.  If the pattern matches a character, the character is
considered to be a word character.  On Windows platforms, words are
comprised of any character that is not a space, tab, or newline.  Under
Unix, words are comprised of numbers, letters or underscores.

.SH "SEE ALSO"
info(n), re_syntax(n)

.SH KEYWORDS
auto-exec, auto-load, library, unknown, word, whitespace 

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\" Copyright (c) 2001 by Kevin B. Kenny.  All rights reserved.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: lindex.n,v 1.13 2007/10/25 09:25:27 dkf Exp $
'\" 
.so man.macros
.TH lindex n 8.4 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
lindex \- Retrieve an element from a list

lindex $a {1 2 3}
.CE
is synonymous with
.CS
lindex [lindex [lindex $a 1] 2] 3
.CE
.SH EXAMPLES
.PP
Demonstrating how the index list system works.
.CS
.ta 5i
\fBlindex\fR {a b c}	 \fB\(->\fI a b c\fR
\fBlindex\fR {a b c} {}	 \fB\(->\fI a b c\fR
\fBlindex\fR {a b c} 0	 \fB\(->\fI a\fR
\fBlindex\fR {a b c} 2	 \fB\(->\fI c\fR
\fBlindex\fR {a b c} end	 \fB\(->\fI c\fR
\fBlindex\fR {a b c} end-1	 \fB\(->\fI b\fR
\fBlindex\fR {{a b c} {d e f} {g h i}} 2 1	 \fB\(->\fI h\fR
\fBlindex\fR {{a b c} {d e f} {g h i}} {2 1}	 \fB\(->\fI h\fR
\fBlindex\fR {{{a b} {c d}} {{e f} {g h}}} 1 1 0	 \fB\(->\fI g\fR
\fBlindex\fR {{{a b} {c d}} {{e f} {g h}}} {1 1 0}	 \fB\(->\fI g\fR
.CE
.SH "SEE ALSO"
list(n), lappend(n), linsert(n), llength(n), lsearch(n), 
lset(n), lsort(n), lrange(n), lreplace(n),
.VS 8.5
string(n)
.VE

.SH KEYWORDS
element, index, list

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\" Copyright (c) 2001 Kevin B. Kenny.  All rights reserved.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: llength.n,v 1.11 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH llength n "" Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
llength \- Count the number of elements in a list
.SH SYNOPSIS
\fBllength \fIlist\fR
.BE

.SH DESCRIPTION
.PP
Treats \fIlist\fR as a list and returns a decimal string giving
the number of elements in it.

.SH EXAMPLES
The result is the number of elements:
.CS
% \fBllength\fR {a b c d e}
5
% \fBllength\fR {a b c}
3

.CE
.PP
An empty list is not necessarily an empty string:
.CS
% set var { }; puts "[string length $var],[\fBllength\fR $var]"
1,0
.CE

.SH "SEE ALSO"
list(n), lappend(n), lindex(n), linsert(n), lsearch(n), 
lset(n), lsort(n), lrange(n), lreplace(n)

.SH KEYWORDS
element, list, length

'\"
'\" Copyright (c) 1995-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: load.n,v 1.18 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH load n 7.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
load \- Load machine code and initialize new commands

package by that name, and uses it if it is found.  If several
different files have been \fBload\fRed with different versions of
the package, Tcl picks the file that was loaded first.
.SH "PORTABILITY ISSUES"
.TP
\fBWindows\fR\0\0\0\0\0
.
When a load fails with a
.QW "library not found"
error, it is also possible that a dependent library was not found.  To
see the dependent libraries, type
.QW "dumpbin -imports <dllname>"
in a DOS console to see what the library must import.
When loading a DLL in the current directory, Windows will ignore
.QW ./
as a path specifier and use a search heuristic to find the DLL instead.
To avoid this, load the DLL with:
.CS
\fBload\fR [file join [pwd] mylib.DLL]
.CE
.SH BUGS
.PP
If the same file is \fBload\fRed by different \fIfileName\fRs, it will

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\" Copyright (c) 2001 Kevin B. Kenny.  All rights reserved.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: lrange.n,v 1.13 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH lrange n 7.4 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
lrange \- Return one or more adjacent elements from a list

end of the list.
.VE
If \fIfirst\fR is less than zero, it is treated as if it were zero.
If \fIlast\fR is greater than or equal to the number of elements
in the list, then it is treated as if it were \fBend\fR.
If \fIfirst\fR is greater than \fIlast\fR then an empty string
is returned.
Note:
.QW "\fBlrange \fIlist first first\fR"
does not always produce the same result as
.QW "\fBlindex \fIlist first\fR"
(although it often does
for simple fields that aren't enclosed in braces); it does, however,
produce exactly the same results as
.QW "\fBlist [lindex \fIlist first\fB]\fR" .
.SH EXAMPLES
Selecting the first two elements:
.CS
% \fBlrange\fR {a b c d e} 0 1
a b
.CE
.PP

'\"
'\" Copyright (c) 2003 by Simon Geard.  All rights reserved.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: lrepeat.n,v 1.3 2007/10/25 09:25:27 dkf Exp $
'\" 
.so man.macros
.TH lrepeat n 8.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
lrepeat \- Build a list by repeating elements
.SH SYNOPSIS
\fBlrepeat \fInumber element1 \fR?\fIelement2 element3 ...\fR?
.BE
.SH DESCRIPTION
.PP
The \fBlrepeat\fR command creates a list of size \fInumber\fR \(mu \fInumber
of elements\fR by repeating \fInumber\fR times the sequence of elements
\fIelement1 element2 ...\fR. The \fInumber\fR must be a positive integer, and
each \fIelementN\fR can be any Tcl value.
.PP
Note that
.QW "\fBlrepeat 1 arg ...\fR"
is identical to
.QW "\fBlist arg ...\fR" ,
though the \fIarg\fR is required with \fBlrepeat\fR.
.SH EXAMPLES
.CS
.ta 3i
lrepeat 3 a	\fB\(->\fI a a a\fR
lrepeat 3 [lrepeat 3 0]	\fB\(->\fI {0 0 0} {0 0 0} {0 0 0}\fR
lrepeat 3 a b c	\fB\(->\fI a b c a b c a b c\fR
lrepeat 3 [lrepeat 2 a] b c	\fB\(->\fI {a a} b c {a a} b c {a a} b c\fR
.CE
.SH "SEE ALSO"
list(n), lappend(n), linsert(n), llength(n), lset(n)

.SH KEYWORDS
element, index, list

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\" Copyright (c) 2001 Kevin B. Kenny.  All rights reserved.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: lreplace.n,v 1.14 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH lreplace n 7.4 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
lreplace \- Replace elements in a list with new elements
.SH SYNOPSIS
\fBlreplace \fIlist first last \fR?\fIelement element ...\fR?
.BE

.SH DESCRIPTION
.PP
\fBlreplace\fR returns a new list formed by replacing one or more elements of
\fIlist\fR with the \fIelement\fR arguments.
.VS 8.5
\fIfirst\fR and \fIlast\fR are index values specifying the first and
last elements of the range to replace.  
The index values \fIfirst\fR and \fIlast\fR are interpreted
the same as index values for the command \fBstring index\fR,
supporting simple index arithmetic and indices relative to the
end of the list.
0 refers to the first element of the
list, and \fBend\fR refers to the last element of the list.
If \fIlist\fR is empty, then \fIfirst\fR and \fIlast\fR are ignored.
.VE
.PP
If \fIfirst\fR is less than zero, it is considered to refer to the
first element of the list.  For non-empty lists, the element indicated
by \fIfirst\fR must exist.
.PP
If \fIlast\fR is less than zero but greater than \fIfirst\fR, then any
specified elements will be prepended to the list.  If \fIlast\fR is
less than \fIfirst\fR then no elements are deleted; the new elements
are simply inserted before \fIfirst\fR.
.PP
The \fIelement\fR arguments specify zero or more new arguments to
be added to the list in place of those that were deleted.
Each \fIelement\fR argument will become a separate element of
the list.  If no \fIelement\fR arguments are specified, then the elements
between \fIfirst\fR and \fIlast\fR are simply deleted.  If \fIlist\fR
is empty, any \fIelement\fR arguments are added to the end of the list.
.SH EXAMPLES

Deleting the last element from a list in a variable:
.CS
% set var {a b c d e}
a b c d e
% set var [\fBlreplace\fR $var end end]
a b c d
.CE

.SH "SEE ALSO"
list(n), lappend(n), lindex(n), linsert(n), llength(n), lsearch(n), 
lset(n), lrange(n), lsort(n),
.VS 8.5
string(n)
.VE


.SH KEYWORDS
element, list, replace

.\" -*- nroff -*-
.\" Copyright (c) 2006 by Donal K. Fellows.  All rights reserved.
.\"
.\" See the file "license.terms" for information on usage and redistribution
.\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
.\" 
.\" RCS: @(#) $Id: lreverse.n,v 1.3 2007/10/25 09:25:27 dkf Exp $
.\" 
.so man.macros
.TH lreverse n 8.5 Tcl "Tcl Built-In Commands"
.BS
.\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
lreverse \- Reverse the order of a list
.SH SYNOPSIS
\fBlreverse \fIlist\fR
.BE
.SH DESCRIPTION
.PP
The \fBlreverse\fR command returns a list that has the same elements as its
input list, \fIlist\fR, except with the elements in the reverse order.
.SH EXAMPLES
.CS
.ta 3i
\fBlreverse\fR {a a b c}	\fB\(->\fI c b a a\fR
\fBlreverse\fR {a b {c d} e f}	\fB\(->\fI f e {c d} b a\fR
.CE
.SH "SEE ALSO"
list(n), lsearch(n), lsort(n)

.SH KEYWORDS
element, list, reverse

'\" 
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\" Copyright (c) 2001 Kevin B. Kenny.  All rights reserved.
'\" Copyright (c) 2003-2004 Donal K. Fellows.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: lsearch.n,v 1.28 2007/10/25 09:25:27 dkf Exp $
'\" 
.so man.macros
.TH lsearch n 8.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
lsearch \- See if a list contains a particular element
.SH SYNOPSIS
\fBlsearch \fR?\fIoptions\fR? \fIlist pattern\fR
.BE

.SH DESCRIPTION
.PP
This command searches the elements of \fIlist\fR to see if one
of them matches \fIpattern\fR.  If so, the command returns the index
of the first matching element
(unless the options \fB\-all\fR or \fB\-inline\fR are specified.)
If not, the command returns \fB\-1\fR.  The \fIoption\fR arguments
indicates how the elements of the list are to be matched against
\fIpattern\fR and must have one of the values below:
.SS "MATCHING STYLE OPTIONS"
If all matching style options are omitted, the default matching style
is \fB\-glob\fR.  If more than one matching style is specified, the
last matching style given takes precedence.
.TP
\fB\-exact\fR
.
\fIPattern\fR is a literal string that is compared for exact equality
against each list element.
.TP
\fB\-glob\fR
.
\fIPattern\fR is a glob-style pattern which is matched against each list
element using the same rules as the \fBstring match\fR command.
.TP
\fB\-regexp\fR
.
\fIPattern\fR is treated as a regular expression and matched against
each list element using the rules described in the \fBre_syntax\fR
reference page.
.TP
\fB\-sorted\fR
.
The list elements are in sorted order.  If this option is specified,
\fBlsearch\fR will use a more efficient searching algorithm to search
\fIlist\fR.  If no other options are specified, \fIlist\fR is assumed
to be sorted in increasing order, and to contain ASCII strings.  This
option is mutually exclusive with \fB\-glob\fR and \fB\-regexp\fR, and
is treated exactly like \fB-exact\fR when either \fB\-all\fR or
\fB\-not\fR are specified.
.SS "GENERAL MODIFIER OPTIONS"
These options may be given with all matching styles.
.TP
\fB\-all\fR
.
Changes the result to be the list of all matching indices (or all matching
values if \fB\-inline\fR is specified as well.) If indices are returned, the
indices will be in numeric order. If values are returned, the order of the
values will be the order of those values within the input \fIlist\fR.
.TP
\fB\-inline\fR
.
The matching value is returned instead of its index (or an empty
string if no value matches.)  If \fB\-all\fR is also specified, then
the result of the command is the list of all values that matched.
.TP
\fB\-not\fR
.
This negates the sense of the match, returning the index of the first
non-matching value in the list.
.TP
\fB\-start\fR\0\fIindex\fR
.
The list is searched starting at position \fIindex\fR.
.VS 8.5
The interpretation of the \fIindex\fR value is the same as
for the command \fBstring index\fR, supporting simple index
arithmetic and indices relative to the end of the list.
.VE 8.5
.SS "CONTENTS DESCRIPTION OPTIONS"
These options describe how to interpret the items in the list being
searched.  They are only meaningful when used with the \fB\-exact\fR
and \fB\-sorted\fR options.  If more than one is specified, the last
one takes precedence.  The default is \fB\-ascii\fR.
.TP
\fB\-ascii\fR
.
The list elements are to be examined as Unicode strings (the name is
for backward-compatibility reasons.)
.TP
\fB\-dictionary\fR
.
The list elements are to be compared using dictionary-style
comparisons (see \fBlsort\fR for a fuller description). Note that this
only makes a meaningful difference from the \fB\-ascii\fR option when
the \fB\-sorted\fR option is given, because values are only
dictionary-equal when exactly equal.
.TP
\fB\-integer\fR
.
The list elements are to be compared as integers.
.VS 8.5
.TP
\fB\-nocase\fR
.
Causes comparisons to be handled in a case-insensitive manner.  Has no
effect if combined with the \fB\-dictionary\fR, \fB\-integer\fR, or 
\fB\-real\fR options.
.VE 8.5
.TP
\fB\-real\fR
.
The list elements are to be compared as floating-point values.
.SS "SORTED LIST OPTIONS"
These options (only meaningful with the \fB\-sorted\fR option) specify
how the list is sorted.  If more than one is given, the last one takes
precedence.  The default option is \fB\-increasing\fR.
.TP
\fB\-decreasing\fR
.
The list elements are sorted in decreasing order.  This option is only
meaningful when used with \fB\-sorted\fR.
.TP
\fB\-increasing\fR
.
The list elements are sorted in increasing order.  This option is only
meaningful when used with \fB\-sorted\fR.
.SS "NESTED LIST OPTIONS"
.VS 8.5
These options are used to search lists of lists.  They may be used
with any other options.
.TP
\fB\-index\fR\0\fIindexList\fR
.
This option is designed for use when searching within nested lists.
The \fIindexList\fR argument gives a path of indices (much as might be
used with the \fBlindex\fR or \fBlset\fR commands) within each element
to allow the location of the term being matched against.
.TP
\fB\-subindices\fR
.
If this option is given, the index result from this command (or every
index result when \fB\-all\fR is also specified) will be a complete
path (suitable for use with \fBlindex\fR or \fBlset\fR) within the
overall list to the term found.  This option has no effect unless the
\fI\-index\fR is also specified, and is just a convenience short-cut.
.VE 8.5
.SH EXAMPLES
Basic searching:
.CS
.ta 2i
\fBlsearch\fR {a b c d e} c
	\fB\(->\fI 2\fR
\fBlsearch\fR -all {a b c a b c} c
	\fB\(->\fI 2 5\fR
.CE
.PP
Using \fBlsearch\fR to filter lists:
.CS
.ta 2i
\fBlsearch\fR -inline {a20 b35 c47} b*
	\fB\(->\fI b35\fR
\fBlsearch\fR -inline -not {a20 b35 c47} b*
	\fB\(->\fI a20\fR
\fBlsearch\fR -all -inline -not {a20 b35 c47} b*
	\fB\(->\fI a20 c47\fR
\fBlsearch\fR -all -not {a20 b35 c47} b*
	\fB\(->\fI 0 2\fR
.CE
This can even do a
.QW set-like
removal operation:
.CS
.ta 2i
\fBlsearch\fR -all -inline -not -exact {a b c a d e a f g a} a
	\fB\(->\fI b c d e f g\fR
.CE
.PP
Searching may start part-way through the list:
.CS
.ta 2i
\fBlsearch\fR -start 3 {a b c a b c} c
	\fB\(->\fI 5\fR
.CE
.PP
It is also possible to search inside elements:
.CS
.ta 2i
\fBlsearch\fR -index 1 -all -inline {{a abc} {b bcd} {c cde}} *bc*
	\fB\(->\fI {a abc} {b bcd}\fR
.CE

.SH "SEE ALSO"
foreach(n), list(n), lappend(n), lindex(n), linsert(n), llength(n), 
lset(n), lsort(n), lrange(n), lreplace(n),
.VS 8.5
string(n)
.VE


.SH KEYWORDS
list, match, pattern, regular expression, search, string

.\" Local Variables:
.\" mode: nroff
.\" End:

'\"
'\" Copyright (c) 2001 by Kevin B. Kenny.  All rights reserved.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: lset.n,v 1.11 2007/10/25 09:25:27 dkf Exp $
'\" 
.so man.macros
.TH lset n 8.4 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
lset \- Change an element in a list

than or equal to zero.  The integer appearing in each \fIindex\fR
argument must be strictly less than the length of the corresponding
list.  In other words, the \fBlset\fR command cannot change the size
of a list.  If an index is outside the permitted range, an error is reported.
.SH EXAMPLES
In each of these examples, the initial value of \fIx\fR is:
.CS
.ta 2i
set x [list [list a b c] [list d e f] [list g h i]]
	 \fB\(->\fR {a b c} {d e f} {g h i}
.CE
The indicated return value also becomes the new value of \fIx\fR
(except in the last case, which is an error which leaves the value of
\fIx\fR unchanged.)
.CS
.ta 2i
lset x {j k l}	 \fB\(->\fR j k l
lset x {} {j k l}	 \fB\(->\fR j k l
lset x 0 j	 \fB\(->\fR j {d e f} {g h i}
lset x 2 j	 \fB\(->\fR {a b c} {d e f} j
lset x end j	 \fB\(->\fR {a b c} {d e f} j
lset x end-1 j	 \fB\(->\fR {a b c} j {g h i}
lset x 2 1 j	 \fB\(->\fR {a b c} {d e f} {g j i}
lset x {2 1} j	 \fB\(->\fR {a b c} {d e f} {g j i}
lset x {2 3} j	 \fB\(->\fR \fIlist index out of range\fR
.CE
In the following examples, the initial value of \fIx\fR is:
.CS
.ta 2i
set x [list [list [list a b] [list c d]] \e
            [list [list e f] [list g h]]]
	 \fB\(->\fR {{a b} {c d}} {{e f} {g h}}
.CE
The indicated return value also becomes the new value of \fIx\fR.
.CS
.ta 2i
lset x 1 1 0 j	 \fB\(->\fR {{a b} {c d}} {{e f} {j h}}
lset x {1 1 0} j	 \fB\(->\fR {{a b} {c d}} {{e f} {j h}}
.CE
.SH "SEE ALSO"
list(n), lappend(n), lindex(n), linsert(n), llength(n), lsearch(n), 
lsort(n), lrange(n), lreplace(n),
.VS 8.5
string(n)
.VE


.SH KEYWORDS
element, index, list, replace, set

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\" Copyright (c) 1999 Scriptics Corporation
'\" Copyright (c) 2001 Kevin B. Kenny.  All rights reserved.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: lsort.n,v 1.23 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH lsort n 8.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
lsort \- Sort the elements of a list

\fIcommand\fR with the two elements appended as additional
arguments.  The script should return an integer less than,
equal to, or greater than zero if the first element is to
be considered less than, equal to, or greater than the second,
respectively.
.TP 20
\fB\-increasing\fR
Sort the list in increasing order (i.e.
.QW smallest
items first). This is the default.
.TP 20
\fB\-decreasing\fR
Sort the list in decreasing order (i.e.
.QW largest
items first).
.TP 20
\fB\-indices\fR
.VS "8.5 (TIP#217)"
Return a list of indices into \fIlist\fR in sorted order instead of
the values themselves.
.VE "8.5 (TIP#217)"
.TP 20

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-2000 Sun Microsystems, Inc.
'\" Copyright (c) 2005 by Kevin B. Kenny <[email protected]>. All rights reserved
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: mathfunc.n,v 1.14 2007/10/25 14:07:32 dkf Exp $
'\" 
.so man.macros
.TH mathfunc n 8.5 Tcl "Tcl Mathematical Functions"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
mathfunc \- Mathematical functions for Tcl expressions

.br
\fB::tcl::mathfunc::wide\fR \fIarg\fR
.sp
.BE
.SH "DESCRIPTION"
.PP
The \fBexpr\fR command handles mathematical functions of the form
.QW \fBsin($x)\fR
or
.QW \fBatan2($y,$x)\fR
by converting them to calls of the form
.QW "\fB[tcl::mathfunc::sin [expr {$x}]]\fR"
or
.QW "\fB[tcl::mathfunc::atan2 [expr {$y}] [expr {$x}]]\fR" .
A number of math functions are available by default within the
namespace \fB::tcl::mathfunc\fR; these functions are also available
for code apart from \fBexpr\fR, by invoking the given commands
directly.
.PP
Tcl supports the following mathematical functions in expressions, all
of which work solely with floating-point numbers unless otherwise noted:

\fBmin\fR	\fBpow\fR	\fBrand\fR	\fBround\fR
\fBsin\fR	\fBsinh\fR	\fBsqrt\fR	\fBsrand\fR
\fBtan\fR	\fBtanh\fR	\fBwide\fR
.DE
.PP
.TP
\fBabs(\fIarg\fB)\fR
.
Returns the absolute value of \fIarg\fR.  \fIArg\fR may be either
integer or floating-point, and the result is returned in the same form.
.TP
\fBacos(\fIarg\fB)\fR
.
Returns the arc cosine of \fIarg\fR, in the range [\fI0\fR,\fIpi\fR]
radians. \fIArg\fR should be in the range [\fI-1\fR,\fI1\fR].
.TP
\fBasin(\fIarg\fB)\fR
.
Returns the arc sine of \fIarg\fR, in the range [\fI-pi/2\fR,\fIpi/2\fR]
radians.  \fIArg\fR should be in the range [\fI-1\fR,\fI1\fR].
.TP
\fBatan(\fIarg\fB)\fR
.
Returns the arc tangent of \fIarg\fR, in the range [\fI-pi/2\fR,\fIpi/2\fR]
radians.
.TP
\fBatan2(\fIy, x\fB)\fR
.
Returns the arc tangent of \fIy\fR/\fIx\fR, in the range [\fI-pi\fR,\fIpi\fR]
radians.  \fIx\fR and \fIy\fR cannot both be 0.  If \fIx\fR is greater
than \fI0\fR, this is equivalent to \fBatan(\fIy/x\fB)\fR.
.TP
\fBbool(\fIarg\fB)\fR
.
Accepts any numeric value, or any string acceptable to
\fBstring is boolean\fR, and returns the corresponding 
boolean value \fB0\fR or \fB1\fR.  Non-zero numbers are true.
Other numbers are false.  Non-numeric strings produce boolean value in
agreement with
.QW "\fBstring is true\fR"
and
.QW "\fBstring is false\fR" .
.TP
\fBceil(\fIarg\fB)\fR
.
Returns the smallest integral floating-point value (i.e. with a zero
fractional part) not less than \fIarg\fR.  The argument may be any
numeric value.
.TP
\fBcos(\fIarg\fB)\fR
.
Returns the cosine of \fIarg\fR, measured in radians.
.TP
\fBcosh(\fIarg\fB)\fR
.
Returns the hyperbolic cosine of \fIarg\fR.  If the result would cause
an overflow, an error is returned.
.TP
\fBdouble(\fIarg\fB)\fR
.
The argument may be any numeric value,
If \fIarg\fR is a floating-point value, returns \fIarg\fR, otherwise converts
\fIarg\fR to floating-point and returns the converted value.  May return
\fBInf\fR or \fB-Inf\fR when the argument is a numeric value that exceeds
the floating-point range.
.TP
\fBentier(\fIarg\fB)\fR
.VS 8.5
The argument may be any numeric value.  The integer part of \fIarg\fR
is determined and returned.  The integer range returned by this function
is unlimited, unlike functions \fBint()\fR and \fBwide()\fR which
truncate their range to fit in particular storage widths.
.VE 8.5
.TP
\fBexp(\fIarg\fB)\fR
.
Returns the exponential of \fIarg\fR, defined as \fIe\fR**\fIarg\fR.
If the result would cause an overflow, an error is returned.
.TP
\fBfloor(\fIarg\fB)\fR
.
Returns the largest integral floating-point value (i.e. with a zero
fractional part) not greater than \fIarg\fR.  The argument may be
any numeric value.
.TP
\fBfmod(\fIx, y\fB)\fR
.
Returns the floating-point remainder of the division of \fIx\fR by
\fIy\fR.  If \fIy\fR is 0, an error is returned.
.TP
\fBhypot(\fIx, y\fB)\fR
.
Computes the length of the hypotenuse of a right-angled triangle
.QW "\fBsqrt(\fIx\fR*\fIx\fR+\fIy\fR*\fIy\fB)\fR" .
.TP
\fBint(\fIarg\fB)\fR
.
The argument may be any numeric value.  The integer part of \fIarg\fR
is determined, and then the low order bits of that integer value up
to the machine word size are returned as an integer value.  For reference,
the number of bytes in the machine word are stored in
\fBtcl_platform(wordSize)\fR.
.TP
\fBisqrt(\fIarg\fB)\fR
.
Computes the integer part of the square root of \fIarg\fR.  \fIArg\fR must be
a positive value, either an integer or a floating point number.
Unlike \fBsqrt\fR, which is limited to the precision of a floating point
number, \fIisqrt\fR will return a result of arbitrary precision.
.TP
\fBlog(\fIarg\fB)\fR
.
Returns the natural logarithm of \fIarg\fR.  \fIArg\fR must be a
positive value.
.TP
\fBlog10(\fIarg\fB)\fR
.
Returns the base 10 logarithm of \fIarg\fR.  \fIArg\fR must be a
positive value.
.TP
\fBmax(\fIarg\fB, \fI...\fB)\fR
.
Accepts one or more numeric arguments.  Returns the one argument
with the greatest value.
.TP
\fBmin(\fIarg\fB, \fI...\fB)\fR
.
Accepts one or more numeric arguments.  Returns the one argument
with the least value.
.TP
\fBpow(\fIx, y\fB)\fR
.
Computes the value of \fIx\fR raised to the power \fIy\fR.  If \fIx\fR
is negative, \fIy\fR must be an integer value.
.TP
\fBrand()\fR
.
Returns a pseudo-random floating-point value in the range (\fI0\fR,\fI1\fR).  
The generator algorithm is a simple linear congruential generator that
is not cryptographically secure.  Each result from \fBrand\fR completely
determines all future results from subsequent calls to \fBrand\fR, so
\fBrand\fR should not be used to generate a sequence of secrets, such as
one-time passwords.  The seed of the generator is initialized from the
internal clock of the machine or may be set with the \fBsrand\fR function.
.TP
\fBround(\fIarg\fB)\fR
.
If \fIarg\fR is an integer value, returns \fIarg\fR, otherwise converts
\fIarg\fR to integer by rounding and returns the converted value.
.TP
\fBsin(\fIarg\fB)\fR
.
Returns the sine of \fIarg\fR, measured in radians.
.TP
\fBsinh(\fIarg\fB)\fR
.
Returns the hyperbolic sine of \fIarg\fR.  If the result would cause
an overflow, an error is returned.
.TP
\fBsqrt(\fIarg\fB)\fR
.
The argument may be any non-negative numeric value.  Returns a floating-point
value that is the square root of \fIarg\fR.  May return \fBInf\fR when the
argument is a numeric value that exceeds the square of the maximum value of
the floating-point range.
.TP
\fBsrand(\fIarg\fB)\fR
.
The \fIarg\fR, which must be an integer, is used to reset the seed for
the random number generator of \fBrand\fR.  Returns the first random
number (see \fBrand()\fR) from that seed.  Each interpreter has its own seed.
.TP
\fBtan(\fIarg\fB)\fR
.
Returns the tangent of \fIarg\fR, measured in radians.
.TP
\fBtanh(\fIarg\fB)\fR
.
Returns the hyperbolic tangent of \fIarg\fR.
.TP
\fBwide(\fIarg\fB)\fR
.
The argument may be any numeric value.  The integer part of \fIarg\fR
is determined, and then the low order 64 bits of that integer value
are returned as an integer value.  
.PP
In addition to these predefined functions, applications may
define additional functions by using \fBproc\fR (or any other method,
such as \fBinterp alias\fR or \fBTcl_CreateObjCommand\fR) to define
new commands in the \fBtcl::mathfunc\fR namespace.  In addition, an
obsolete interface named \fBTcl_CreateMathFunc\fR() is available to
extensions that are written in C. The latter interface is not recommended
for new implementations.
.SH "SEE ALSO"
expr(n), namespace(n)
.SH "COPYRIGHT"
.nf
Copyright \(co 1993 The Regents of the University of California.

Copyright \(co 1994-2000 Sun Microsystems Incorporated.

Copyright \(co 2005, 2006 by Kevin B. Kenny <[email protected]>.
.fi

.\" -*- nroff -*-
.\" Copyright (c) 2006 Donal K. Fellows.
.\"
.\" See the file "license.terms" for information on usage and redistribution
.\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
.\"
.\" RCS: @(#) $Id: mathop.n,v 1.5 2007/10/25 14:07:32 dkf Exp $
.\"
.so man.macros
.TH mathop n 8.5 Tcl "Tcl Mathematical Operator Commands"
.BS
.\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
mathop \- Mathematical operators as Tcl commands

Returns the integral modulus of the first argument with respect to the second.
Each \fInumber\fR must have an integral value.
.TP
\fB**\fR ?\fInumber\fR ...?
.
Returns the result of raising each value to the power of the result of
recursively operating on the result of processing the following arguments, so
.QW "\fB** 2 3 4\fR"
is the same as
.QW "\fB** 2 [** 3 4]\fR" .
Each \fInumber\fR may be
any numeric value, though the second number must not be fractional if the
first is negative. If no arguments are given, the result will be one, and if
only one argument is given, the result will be that argument.
.TP
\fB&\fR ?\fInumber\fR ...?
.
Returns the bit-wise AND of each of the arbitrarily many arguments. Each

'\"
'\" Copyright (c) 1992-1999 by Karl Lehenbauer and Mark Diekhans
'\" Copyright (c) 2000 by Scriptics Corporation.
'\" All rights reserved.
'\" 
'\" RCS: @(#) $Id: memory.n,v 1.7 2007/10/25 14:07:32 dkf Exp $
'\" 
.so man.macros
.TH memory n 8.1 Tcl "Tcl Built-In Commands"
.BS
.SH NAME
memory \- Control Tcl memory debugging capabilities
.SH SYNOPSIS
\fBmemory \fIoption \fR?\fIarg arg ...\fR?
.BE

.SH DESCRIPTION
.PP
The \fBmemory\fR command gives the Tcl developer control of Tcl's memory
debugging capabilities.  The memory command has several suboptions, which are
described below.  It is only available when Tcl has been compiled with
memory debugging enabled (when \fBTCL_MEM_DEBUG\fR is defined at
compile time), and after \fBTcl_InitMemory\fR has been called.
.TP
\fBmemory active\fR \fIfile\fR
.
Write a list of all currently allocated memory to the specified \fIfile\fR.
.TP
\fBmemory break_on_malloc\fR \fIcount\fR
.
After the \fIcount\fR allocations have been performed, \fBckalloc\fR
outputs a message to this effect and that it is now attempting to enter
the C debugger.  Tcl will then issue a \fISIGINT\fR signal against itself.
If you are running Tcl under a C debugger, it should then enter the debugger
command mode.
.TP
\fBmemory info\fR
.
Returns a report containing the total allocations and frees since 
Tcl began, the current packets allocated (the current
number of calls to \fBckalloc\fR not met by a corresponding call 
to \fBckfree\fR), the current bytes allocated, and the maximum number
of packets and bytes allocated.
.TP
\fBmemory init \fR[\fBon\fR|\fBoff\fR]
.
Turn on or off the pre-initialization of all allocated memory
with bogus bytes.  Useful for detecting the use of uninitialized values.
.TP
\fBmemory onexit\fR \fIfile\fR
.
Causes a list of all allocated memory to be written to the specified \fIfile\fR
during the finalization of Tcl's memory subsystem.  Useful for checking
that memory is properly cleaned up during process exit.
.TP
\fBmemory tag\fR \fIstring\fR
.
Each packet of memory allocated by \fBckalloc\fR can have associated
with it a string-valued tag.  In the lists of allocated memory generated
by \fBmemory active\fR and \fBmemory onexit\fR, the tag for each packet
is printed along with other information about the packet.  The
\fBmemory tag\fR command sets the tag value for subsequent calls
to \fBckalloc\fR to be \fIstring\fR.  
.TP
\fBmemory trace \fR[\fBon\fR|\fBoff\fR]
.
Turns memory tracing on or off.  When memory tracing is on, every call
to \fBckalloc\fR causes a line of trace information to be written to
\fIstderr\fR, consisting of the word \fIckalloc\fR, followed by the
address returned, the amount of memory allocated, and the C filename
and line number of the code performing the allocation.  For example:
.RS
.CS
ckalloc 40e478 98 tclProc.c 1406
.CE
Calls to \fBckfree\fR are traced in the same manner.
.RE
.TP
\fBmemory trace_on_at_malloc\fR \fIcount\fR
.
Enable memory tracing after \fIcount\fR \fBckalloc\fRs have been performed.
For example, if you enter
.QW "\fBmemory trace_on_at_malloc 100\fR" ,
.
after the 100th call to \fBckalloc\fR, memory trace information will begin
being displayed for all allocations and frees.  Since there can be a lot
of memory activity before a problem occurs, judicious use of this option
can reduce the slowdown caused by tracing (and the amount of trace information
produced), if you can identify a number of allocations that occur before
the problem sets in.  The current number of memory allocations that have 
occurred since Tcl started is printed on a guard zone failure.
.TP
\fBmemory validate \fR[\fBon\fR|\fBoff\fR]
.
Turns memory validation on or off. When memory validation is enabled,
on every call to \fBckalloc\fR or \fBckfree\fR, the guard zones are
checked for every piece of memory currently in existence that was
allocated by \fBckalloc\fR.  This has a large performance impact and
should only be used when overwrite problems are strongly suspected.
The advantage of enabling memory validation is that a guard zone
overwrite can be detected on the first call to \fBckalloc\fR or
\fBckfree\fR after the overwrite occurred, rather than when the
specific memory with the overwritten guard zone(s) is freed, which may
occur long after the overwrite occurred.

.SH "SEE ALSO"
ckalloc(3), ckfree(3), Tcl_ValidateAllMemory(3), Tcl_DumpActiveMemory(3),
TCL_MEM_DEBUG
.SH KEYWORDS
memory, debug

.sp
\fB::msgcat::mcset \fIlocale src-string \fR?\fItranslate-string\fR?
.sp
\fB::msgcat::mcmset \fIlocale src-trans-list\fR
.sp
\fB::msgcat::mcunknown \fIlocale src-string\fR
.BE

.SH DESCRIPTION
.PP
The \fBmsgcat\fR package provides a set of functions
that can be used to manage multi-lingual user interfaces.
Text strings are defined in a
.QW "message catalog"
which is independent from the application, and
which can be edited or localized without modifying
the application source code.  New languages
or locales are provided by adding a new file to
the message catalog.
.PP
Use of the message catalog is optional by any application
or package, but is encouraged if the application or package

the user, based on the user's language specification.
The list is ordered from most specific to least
preference.  The list is derived from the current
locale set in msgcat by \fB::msgcat::mclocale\fR, and
cannot be set independently.  For example, if the
current locale is en_US_funky, then \fB::msgcat::mcpreferences\fR
.VS 1.4
returns
.QW "\fBen_US_funky en_US en {}\fR" .
.VE 1.4
.TP
\fB::msgcat::mcload \fIdirname\fR
Searches the specified directory for files that match
the language specifications returned by \fB::msgcat::mcpreferences\fR
(note that these are all lowercase), extended by the file extension
.QW .msg .
Each matching file is 
read in order, assuming a UTF-8 encoding.  The file contents are
then evaluated as a Tcl script.  This means that Unicode characters
may be present in the message file either directly in their UTF-8
encoded form, or by use of the backslash-u quoting recognized by Tcl
evaluation.  The number of message files which matched the specification
and were loaded is returned.
.TP
\fB::msgcat::mcset \fIlocale src-string \fR?\fItranslate-string\fR?
Sets the translation for \fIsrc-string\fR to \fItranslate-string\fR
in the specified \fIlocale\fR and the current namespace.  If
\fItranslate-string\fR is not specified, \fIsrc-string\fR is used
for both.  The function returns \fItranslate-string\fR.
.TP
\fB::msgcat::mcmset \fIlocale src-trans-list\fR
Sets the translation for multiple source strings in
\fIsrc-trans-list\fR in the specified \fIlocale\fR and the current
namespace.
\fIsrc-trans-list\fR must have an even number of elements and is in
the form
.QW "\fIsrc-string translate-string\fR ?\fIsrc-string translate-string ...\fR?}" .
The \fB::msgcat::mcmset\fR command can be significantly
faster than multiple invocations of \fB::msgcat::mcset\fR. The function
returns the number of translations set.
.TP
\fB::msgcat::mcunknown \fIlocale src-string\fR
This routine is called by \fB::msgcat::mc\fR in the case when
a translation for \fIsrc-string\fR is not defined in the
current locale.  The default action is to return
\fIsrc-string\fR.  This procedure can be redefined by the
application, for example to log error messages for each unknown
string.  The \fB::msgcat::mcunknown\fR procedure is invoked at the
same stack context as the call to \fB::msgcat::mc\fR.  The return value
of \fB::msgcat::mcunknown\fR is used as the return value for the call
to \fB::msgcat::mc\fR.  
.SH "LOCALE SPECIFICATION"
.PP
The locale is specified to \fBmsgcat\fR by a locale string
passed to \fB::msgcat::mclocale\fR.
The locale string consists of
a language code, an optional country code, and an optional
system-specific code, each separated by
.QW _ .
The country and language
codes are specified in standards ISO-639 and ISO-3166.
For example, the locale
.QW en
specifies English and
.QW en_US
specifies U.S. English.
.PP
When the msgcat package is first loaded, the locale is initialized
according to the user's environment.  The variables \fBenv(LC_ALL)\fR,
\fBenv(LC_MESSAGES)\fR, and \fBenv(LANG)\fR are examined in order.
The first of them to have a non-empty value is used to determine the
initial locale.  The value is parsed according to the XPG4 pattern
.CS
language[_country][.codeset][@modifier]
.CE
to extract its parts.  The initial locale is then set by calling
\fB::msgcat::mclocale\fR with the argument 
.CS
language[_country][_modifier]
.CE
On Windows, if none of those environment variables is set, msgcat will
attempt to extract locale information from the
registry.  If all these attempts to discover an initial locale
from the user's environment fail, msgcat defaults to an initial
locale of
.QW C .
.PP
When a locale is specified by the user, a
.QW "best match"
search is
performed during string translation.  For example, if a user specifies
.VS 1.4
en_GB_Funky, the locales
.QW en_GB_Funky ,
.QW en_GB ,
.QW en
and
.MT
(the empty string)
.VE 1.4
are searched in order until a matching translation
string is found.  If no translation string is available, then
\fB::msgcat::mcunknown\fR is called.
.SH "NAMESPACES AND MESSAGE CATALOGS"
.PP

hello from ::
hello from ::foo
.CE
.PP
When searching for a translation of a message, the
message catalog will search first the current namespace,
then the parent of the current namespace, and so on until
the global namespace is reached.  This allows child namespaces to
.QW inherit
messages from their parent namespace.
.PP
For example, executing (in the
.QW en
locale) the code 
.CS
\fB::msgcat::mcset\fR en m1 ":: message1"
\fB::msgcat::mcset\fR en m2 ":: message2"
\fB::msgcat::mcset\fR en m3 ":: message3"
namespace eval ::foo {
   \fB::msgcat::mcset\fR en m2 "::foo message2"
   \fB::msgcat::mcset\fR en m3 "::foo message3"

.PP
Message files can be located in any directory, subject
to the following conditions:
.IP [1]
All message files for a package are in the same directory.
.IP [2]
The message file name is a msgcat locale specifier (all lowercase)
followed by
.QW .msg .
For example:
.RS
.CS
es.msg    -- spanish
en_gb.msg -- United Kingdom English
.CE
.VS 1.4
\fIException:\fR The message file for the root locale
.MT
is called \fBROOT.msg\fR.  This exception is made so as not to
cause peculiar behavior, such as marking the message file as
.QW hidden
on Unix file systems.
.VE 1.4
.RE
.IP [3]
The file contains a series of calls to \fBmcset\fR and
\fBmcmset\fR, setting the necessary translation strings
for the language, likely enclosed in a \fBnamespace eval\fR
so that all source strings are tied to the namespace of
the package. For example, a short \fBes.msg\fR might contain:
.RS
.CS
namespace eval ::mypackage {
   \fB::msgcat::mcset\fR es "Free Beer!" "Cerveza Gracias!"
}
.CE
.RE
.SH "RECOMMENDED MESSAGE SETUP FOR PACKAGES"
.PP
If a package is installed into a subdirectory of the
\fBtcl_pkgPath\fR and loaded via \fBpackage require\fR, the
following procedure is recommended.
.IP [1]
During package installation, create a subdirectory
\fBmsgs\fR under your package directory.
.IP [2]
Copy your *.msg files into that directory.
.IP [3]
Add the following command to your package initialization script:
.RS

.CS
# load language files, stored in msgs subdirectory
\fB::msgcat::mcload\fR [file join [file dirname [info script]] msgs]
.CE
.RE
.SH "POSITIONAL CODES FOR FORMAT AND SCAN COMMANDS"
.PP
It is possible that a message string used as an argument
to \fBformat\fR might have positionally dependent parameters that
might need to be repositioned.  For example, it might be
syntactically desirable to rearrange the sentence structure
while translating.
.CS
format "We produced %d units in location %s" $num $city
format "In location %s we produced %d units" $city $num
.CE
.PP
This can be handled by using the positional parameters:

.CS
format "We produced %1\\$d units in location %2\\$s" $num $city
format "In location %2\\$s we produced %1\\$d units" $num $city
.CE
.PP
Similarly, positional parameters can be used with \fBscan\fR to
extract values from internationalized strings.
.PP
\fINote:\fR for the specific case of formatting a string, you should
take advantage of the fact that the \fB::msgcat::mc\fR command already
passes its string through \fBformat\fR internally.
.SH CREDITS
.PP
The message catalog code was developed by Mark Harrison.

.SH "SEE ALSO"
format(n), scan(n), namespace(n), package(n)

.SH KEYWORDS
internationalization, i18n, localization, l10n, message, text, translation

'\"
'\" Copyright (c) 1993-1997 Bell Labs Innovations for Lucent Technologies
'\" Copyright (c) 1997 Sun Microsystems, Inc.
'\" Copyright (c) 2000 Scriptics Corporation.
'\" Copyright (c) 2004-2005 Donal K. Fellows.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: namespace.n,v 1.22 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH namespace n 8.5 Tcl "Tcl Built-In Commands"
.BS
.\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
namespace \- create and manipulate contexts for commands and variables
.SH SYNOPSIS
\fBnamespace \fR?\fIoption\fR? ?\fIarg ...\fR?
.BE

.SH DESCRIPTION

The new script has two important properties.
First, it can be evaluated in any namespace and will cause
\fIscript\fR to be evaluated in the current namespace
(the one where the \fBnamespace code\fR command was invoked).
Second, additional arguments can be appended to the resulting script
and they will be passed to \fIscript\fR as additional arguments.
For example, suppose the command
.QW "\fBset script [namespace code {foo bar}]\fR"
is invoked in namespace \fB::a::b\fR.
Then
.QW \fBeval\0"$script\0x\0y"\fR
can be executed in any namespace (assuming the value of
\fBscript\fR has been passed in properly)
and will have the same effect as the command
\fB::namespace eval ::a::b {foo bar x y}\fR.
This command is needed because
extensions like Tk normally execute callback scripts
in the global namespace.
A scoped command captures a command together with its namespace context
in a way that allows it to be executed properly later.
See the section \fBSCOPED SCRIPTS\fR for some examples
of how this is used to create callback scripts.
.TP
\fBnamespace current\fR
Returns the fully-qualified name for the current namespace.
The actual name of the global namespace is
.MT
(i.e., an empty string),
but this command returns \fB::\fR for the global namespace
as a convenience to programmers.
.TP
\fBnamespace delete \fR?\fInamespace namespace ...\fR?
Each namespace \fInamespace\fR is deleted
and all variables, procedures, and child namespaces

\fBnamespace parent\fR ?\fInamespace\fR?
Returns the fully-qualified name of the parent namespace
for namespace \fInamespace\fR.
If \fInamespace\fR is not specified,
the fully-qualified name of the current namespace's parent is returned.
.TP
\fBnamespace path\fR ?\fInamespaceList\fR?
.\" Should really have the .TP inside the .VS, but that triggers a groff bug
.VS 8.5
Returns the command resolution path of the current namespace. If
\fInamespaceList\fR is specified as a list of named namespaces, the
current namespace's command resolution path is set to those namespaces
and returns the empty list. The default command resolution path is
always empty. See the section \fBNAME RESOLUTION\fR below for an
explanation of the rules regarding name resolution.

Since namespaces may nest,
qualified names are used to refer to
commands, variables, and child namespaces contained inside namespaces.
Qualified names are similar to the hierarchical path names for
Unix files or Tk widgets,
except that \fB::\fR is used as the separator
instead of \fB/\fR or \fB.\fR.
The topmost or global namespace has the name
.MT
(i.e., an empty string), although \fB::\fR is a synonym.
As an example, the name \fB::safe::interp::create\fR
refers to the command \fBcreate\fR in the namespace \fBinterp\fR
that is a child of namespace \fB::safe\fR,
which in turn is a child of the global namespace, \fB::\fR.
.PP
If you want to access commands and variables from another namespace,
you must use some extra syntax.

foobar grill
.CE
.PP
Look up where the command imported in the previous example came from:
.CS
puts "grill came from [\fBnamespace origin\fR grill]"
.CE

.SH "SEE ALSO"
interp(n), upvar(n), variable(n)

.SH KEYWORDS
command, ensemble, exported, internal, variable

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: open.n,v 1.29 2007/10/24 14:29:38 dkf Exp $
'\" 
.so man.macros
.TH open n 8.3 Tcl "Tcl Built-In Commands"
.BS
.\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
open \- Open a file-based or command pipeline channel
.SH SYNOPSIS
.sp
\fBopen \fIfileName\fR
.br
\fBopen \fIfileName access\fR

create a new empty file.
Set the initial access position  to the end of the file.
.VS 8.5
.PP
All of the legal \fIaccess\fR values above may have the character
\fBb\fR added as the second or third character in the value to
indicate that the opened channel should be configured with the
\fB\-translation binary\fR option, making the channel suitable for 
reading or writing of binary data.
.VE 8.5
.PP
In the second form, \fIaccess\fR consists of a list of any of the
following flags, all of which have the standard POSIX meanings.
One of the flags must be either \fBRDONLY\fR, \fBWRONLY\fR or \fBRDWR\fR.
.TP 15

Open the file for both reading and writing.
.TP 15
\fBAPPEND\fR
Set the file pointer to the end of the file prior to each write.
.VS 8.5
.TP 15
\fBBINARY\fR
Configure the opened channel with the \fB\-translation binary\fR option.
.VE 8.5
.TP 15
\fBCREAT\fR
Create the file if it doesn't already exist (without this flag it
is an error for the file not to exist).
.TP 15
\fBEXCL\fR

\fBTRUNC\fR
If the file exists it is truncated to zero length.
.PP
If a new file is created as part of opening it, \fIpermissions\fR
(an integer) is used to set the permissions for the new file in
conjunction with the process's file mode creation mask.
\fIPermissions\fR defaults to 0666.

.SH "COMMAND PIPELINES"
.PP
If the first character of \fIfileName\fR is
.QW |
then the remaining characters of \fIfileName\fR are treated as a list of
arguments that describe a command pipeline to invoke, in the same style as the
arguments for \fBexec\fR.
In this case, the channel identifier returned by \fBopen\fR may be used
to write to the command's input pipe or read from its output pipe,
depending on the value of \fIaccess\fR.
If write-only access is used (e.g. \fIaccess\fR is \fBw\fR), then
standard output for the pipeline is directed to the current standard
output unless overridden by the command.