Tcl Source Code

2006-04-25  Don Porter  <[email protected]>

	* doc/DoubleObj.3:	More doc updates for TIP 237.

	* doc/format.n:

	* doc/scan.n:


	* generic/tclScan.c:	[scan $s %u] is documented to accept only
	* tests/scan.test:	decimal formatted integers.  Fixed code to
	match.

2006-04-19  Kevin B. Kenny  <[email protected]>

2006-04-25  Don Porter  <[email protected]>

	* doc/DoubleObj.3:	More doc updates for TIP 237.
	* doc/expr.n:
	* doc/format.n:
	* doc/mathfunc.n:
	* doc/scan.n:
	* doc/string.n:

	* generic/tclScan.c:	[scan $s %u] is documented to accept only
	* tests/scan.test:	decimal formatted integers.  Fixed code to
	match.

2006-04-19  Kevin B. Kenny  <[email protected]>

'\" 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 1.21 2005/06/09 14:24:06 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
................................................................................
\fBexpr \fIarg \fR?\fIarg arg ...\fR?
.BE

.SH DESCRIPTION
.PP
Concatenates \fIarg\fRs (adding separator spaces between them),
evaluates the result as a Tcl expression, and returns the value.
The operators permitted in Tcl expressions are a subset of
the operators permitted in C expressions, and they have the

same meaning and precedence as the corresponding C operators.
Expressions almost always yield numeric results
(integer or floating-point values).
For example, the expression
.CS
\fBexpr 8.2 + 6\fR
.CE
evaluates to 14.2.
Tcl expressions differ from C expressions in the way that
operands are specified.  Also, Tcl expressions support
non-numeric operands and string comparisons.

.SS OPERANDS
.PP
A Tcl expression consists of a combination of operands, operators,
and parentheses.
White space may be used between the operands and operators and
parentheses; it is ignored by the expression's instructions.
Where possible, operands are interpreted as integer values.

Integer values may be specified in decimal (the normal case), in octal (if the
first character of the operand is \fB0\fR), or in hexadecimal (if the first


two characters of the operand are \fB0x\fR).



If an operand does not have one of the integer formats given
above, then it is treated as a floating-point number if that is
possible.  Floating-point numbers may be specified in any of the
ways accepted by an ANSI-compliant C compiler (except that the
\fBf\fR, \fBF\fR, \fBl\fR, and \fBL\fR suffixes will not be permitted in


most installations).  For example, all of the
following are valid floating-point numbers:  2.1, 3., 6e4, 7.91e+16.



If no numeric interpretation is possible (note that all literal
operands that are not numeric or boolean must be quoted with either
braces or with double quotes), then an operand is left as a string
(and only a limited set of operators may be applied to it).
.PP
On 32-bit systems, integer values MAX_INT (0x7FFFFFFF) and MIN_INT
(-0x80000000) will be represented as 32-bit values, and integer values
outside that range will be represented as 64-bit values (if that is
possible at all.)
.PP
Operands may be specified in any of the following ways:
.IP [1]
As a numeric value, either integer or floating-point.
.IP [2]
As a boolean value, using any form understood by \fBstring is boolean\fR.
.IP [3]
As a Tcl variable, using standard \fB$\fR notation.
................................................................................
may as well (depending on the current \fBnamespace path\fR setting).
.PP
See the \fBmathfunc\fR(n) manual page for the math functions that are
available by default.
.VE 8.5
.SS "TYPES, OVERFLOW, AND PRECISION"
.PP

All internal computations involving integers are done with the C type










\fIlong\fR, and all internal computations involving floating-point are
done with the C type \fIdouble\fR.
When converting a string to floating-point, exponent overflow is
detected and results in a Tcl error.
For conversion to integer from string, detection of overflow depends
on the behavior of some routines in the local C library, so it should
be regarded as unreliable.
In any case, integer overflow and underflow are generally not detected
reliably for intermediate results.  Floating-point overflow and underflow
are detected to the degree supported by the hardware, which is generally
pretty reliable.
.PP
Conversion among internal representations for integer, floating-point,
and string operands is done automatically as needed.
For arithmetic computations, integers are used until some
floating-point number is introduced, after which floating-point is used.
................................................................................
.SS "STRING OPERATIONS"
.PP
String values may be used as operands of the comparison operators,
although the expression evaluator tries to do comparisons as integer
or floating-point when it can,
except in the case of the \fBeq\fR and \fBne\fR operators.
If one of the operands of a comparison is a string and the other
has a numeric value, the numeric operand is converted back to
a string using the C \fIsprintf\fR format specifier
\fB%d\fR for integers and \fB%g\fR for floating-point values.


For example, the commands
.CS
\fBexpr {"0x03" > "2"}\fR
\fBexpr {"0y" < "0x12"}\fR
.CE
both return 1.  The first comparison is done using integer
comparison, and the second is done using string comparison after
the second operand is converted to the string \fB18\fR.

'\" 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 1.22 2006/04/26 04:41:10 dgp 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
................................................................................
\fBexpr \fIarg \fR?\fIarg arg ...\fR?
.BE

.SH DESCRIPTION
.PP
Concatenates \fIarg\fRs (adding separator spaces between them),
evaluates the result as a Tcl expression, and returns the value.
The operators permitted in Tcl expressions include a subset of
the operators permitted in C expressions.  For those operators
common to both Tcl and C, Tcl applies the same meaning and precedence
as the corresponding C operators.
Expressions almost always yield numeric results
(integer or floating-point values).
For example, the expression
.CS
\fBexpr 8.2 + 6\fR
.CE
evaluates to 14.2.
Tcl expressions differ from C expressions in the way that
operands are specified.  Also, Tcl expressions support
non-numeric operands and string comparisons, as well as some
additional operators not found in C.
.SS OPERANDS
.PP
A Tcl expression consists of a combination of operands, operators,
and parentheses.
White space may be used between the operands and operators and
parentheses; it is ignored by the expression's instructions.
Where possible, operands are interpreted as integer values.
.VS 8.5
Integer values may be specified in decimal (the normal case), in binary

(if the first two characters of the operand are \fB0b\fR), in octal
(if the first two characters of the operand are \fB0o\fR), or in hexadecimal
(if the first two characters of the operand are \fB0x\fR).  For
compatibility with older Tcl releases, an octal integer value is also
indicated simply when the first character of the operand is \fB0\fR,
whether or not the second character is also \fBo\fR.
If an operand does not have one of the integer formats given
above, then it is treated as a floating-point number if that is
possible.  Floating-point numbers may be specified in any of several


common formats making use of the decimal digits, the decimal point \fB.\fR,
the characters \fBe\fR or \fBE\fR indicating scientific notation, and
the sign characters \fB+\fR or \fB-\fR.  For example, all of the
following are valid floating-point numbers:  2.1, 3., 6e4, 7.91e+16.
Also recognized as floating point values are the strings \fBInf\fR
and \fBNaN\fR making use of any case for each character.
.VE 8.5
If no numeric interpretation is possible (note that all literal
operands that are not numeric or boolean must be quoted with either
braces or with double quotes), then an operand is left as a string
(and only a limited set of operators may be applied to it).
.PP





Operands may be specified in any of the following ways:
.IP [1]
As a numeric value, either integer or floating-point.
.IP [2]
As a boolean value, using any form understood by \fBstring is boolean\fR.
.IP [3]
As a Tcl variable, using standard \fB$\fR notation.
................................................................................
may as well (depending on the current \fBnamespace path\fR setting).
.PP
See the \fBmathfunc\fR(n) manual page for the math functions that are
available by default.
.VE 8.5
.SS "TYPES, OVERFLOW, AND PRECISION"
.PP
.VS 8.5
All internal computations involving integers are done calling on the
LibTomMath multiple precision integer library as required so that all
integer calculations are performed exactly.  Note that in Tcl releases
prior to 8.5, integer calculations were performed with one of the C types
\fIlong int\fR or \fITcl_WideInt\fR, causing implicit range truncation
in those calculations where values overflowed the range of those types.
Any code that relied on these implicit trunctions will need to explicitly
add \fBint()\fR or \fBwide()\fR function calls to expressions at the points
where such truncation is required to take place.
.VE 8.5
.PP
All internal computations involving floating-point are
done with the C type \fIdouble\fR.
When converting a string to floating-point, exponent overflow is
detected and results in the \fIdouble\fR value of \fBInf\fR or




\fB-Inf\fR as appropriate.  Floating-point overflow and underflow
are detected to the degree supported by the hardware, which is generally
pretty reliable.
.PP
Conversion among internal representations for integer, floating-point,
and string operands is done automatically as needed.
For arithmetic computations, integers are used until some
floating-point number is introduced, after which floating-point is used.
................................................................................
.SS "STRING OPERATIONS"
.PP
String values may be used as operands of the comparison operators,
although the expression evaluator tries to do comparisons as integer
or floating-point when it can,
except in the case of the \fBeq\fR and \fBne\fR operators.
If one of the operands of a comparison is a string and the other
has a numeric value, a canonical string representation of the numeric
operand value is generated to compare with the string operand.
Canonical string representation for integer values is a decimal string
format.  Canonical string representation for floating-point values
is that produced by the \fB%g\fR format specifier of Tcl's
\fBformat\fR command.  For example, the commands
.CS
\fBexpr {"0x03" > "2"}\fR
\fBexpr {"0y" < "0x12"}\fR
.CE
both return 1.  The first comparison is done using integer
comparison, and the second is done using string comparison after
the second operand is converted to the string \fB18\fR.

'\" 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 1.8 2005/12/12 16:06:50 kennykb 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::cos\fR \fIarg\fR
.br
\fB::tcl::mathfunc::cosh\fR \fIarg\fR
.br
\fB::tcl::mathfunc::double\fR \fIarg\fR
.br




\fB::tcl::mathfunc::exp\fR \fIarg\fR
.br
\fB::tcl::mathfunc::floor\fR \fIarg\fR
.br
\fB::tcl::mathfunc::fmod\fR \fIx\fR \fIy\fR
.br
\fB::tcl::mathfunc::hypot\fR \fIx\fR \fIy\fR
................................................................................
.PP
Tcl supports the following mathematical functions in expressions, all
of which work solely with floating-point numbers unless otherwise noted:
.DS
.ta 3c 6c 9c
\fBabs\fR	\fBacos\fR	\fBasin\fR	\fBatan\fR
\fBatan2\fR	\fBbool\fR	\fBceil\fR	\fBcos\fR
\fBcosh\fR	\fBdouble\fR	\fBexp\fR	\fBfloor\fR
\fBfmod\fR	\fBhypot\fR	\fBint\fR	\fBlog\fR
\fBlog10\fR	\fBmax\fR	\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
................................................................................
.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 numerical 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 \fBstring is true\fR and \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.

.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

If \fIarg\fR is a floating-point value, returns \fIarg\fR, otherwise converts
\fIarg\fR to floating-point and returns the converted value.


.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.

.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
\fBsqrt(\fIx\fR*\fIx\fR+\fIy\fR*\fIy\fB)\fR.
.TP
\fBint(\fIarg\fB)\fR
If \fIarg\fR is an integer value of the same width as the machine
word, returns \fIarg\fR, otherwise
converts \fIarg\fR to an integer (of the same size as a machine word,
i.e. 32-bits on 32-bit systems, and 64-bits on 64-bit systems) by
truncation and returns the converted value.
.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
Returns the maximum value of all given numeric arguments.

.TP
\fBmin(\fIarg\fB, \fI...\fB)\fR
Returns the minimum value of all given numeric arguments.


.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).  
................................................................................
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

Returns the square root of \fIarg\fR.  \fIArg\fR must be non-negative.


.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
Converts \fIarg\fR to an integer value at least 64-bits wide (by sign-extension
if \fIarg\fR is a 32-bit number) if it is not one already.

.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"
Copyright (c) 1993 The Regents of the University of California.
.br
Copyright (c) 1994-2000 Sun Microsystems Incorporated.
.br
Copyright (c) 2005 by Kevin B. Kenny <[email protected]>. All rights reserved.

'\" 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 1.9 2006/04/26 04:41:10 dgp 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::cos\fR \fIarg\fR
.br
\fB::tcl::mathfunc::cosh\fR \fIarg\fR
.br
\fB::tcl::mathfunc::double\fR \fIarg\fR
.br
.VS 8.5
\fB::tcl::mathfunc::entier\fR \fIarg\fR
.br
.VE 8.5
\fB::tcl::mathfunc::exp\fR \fIarg\fR
.br
\fB::tcl::mathfunc::floor\fR \fIarg\fR
.br
\fB::tcl::mathfunc::fmod\fR \fIx\fR \fIy\fR
.br
\fB::tcl::mathfunc::hypot\fR \fIx\fR \fIy\fR
................................................................................
.PP
Tcl supports the following mathematical functions in expressions, all
of which work solely with floating-point numbers unless otherwise noted:
.DS
.ta 3c 6c 9c
\fBabs\fR	\fBacos\fR	\fBasin\fR	\fBatan\fR
\fBatan2\fR	\fBbool\fR	\fBceil\fR	\fBcos\fR
\fBcosh\fR	\fBdouble\fR	\fBentier\fR	\fBexp\fR
\fBfloor\fR	\fBfmod\fR	\fBhypot\fR	\fBint\fR
\fBlog\fR	\fBlog10\fR	\fBmax\fR	\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
................................................................................
.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 \fBstring is true\fR and \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.
.TP
.VE 8.5
\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
\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
\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).  
................................................................................
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 value acceptable to
\fBstring is integer\fR (that is, a 32-bit 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"
Copyright (c) 1993 The Regents of the University of California.
.br
Copyright (c) 1994-2000 Sun Microsystems Incorporated.
.br
Copyright (c) 2005 by Kevin B. Kenny <[email protected]>. All rights reserved.

'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 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: scan.n,v 1.16 2006/04/25 17:15:25 dgp Exp $
'\" 
.so man.macros
.TH scan n 8.4 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
scan \- Parse string using conversion specifiers in the style of sscanf
................................................................................
value, and the corresponding unsigned value for that truncated
range is computed and stored in the variable as a decimal string.
The conversion makes no sense without refernce to a truncation range,
so the size modifer \fBll\fR is not permitted in combination
with conversion character \fBu\fR.
.TP 10
\fBi\fR 
The input substring must be an integer.  The base (i.e. decimal, octal, or
hexadecimal) is determined in the same fashion as described in
\fBexpr\fR.  The integer value is stored in the variable,
truncated as required by the size modifier value.
.TP 10
\fBc\fR
A single character is read in and its Unicode value is stored in 
the variable as an integer value.
Initial white space is not skipped in this case, so the input

'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 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: scan.n,v 1.17 2006/04/26 04:41:10 dgp Exp $
'\" 
.so man.macros
.TH scan n 8.4 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
scan \- Parse string using conversion specifiers in the style of sscanf
................................................................................
value, and the corresponding unsigned value for that truncated
range is computed and stored in the variable as a decimal string.
The conversion makes no sense without refernce to a truncation range,
so the size modifer \fBll\fR is not permitted in combination
with conversion character \fBu\fR.
.TP 10
\fBi\fR 
The input substring must be an integer.  The base (i.e. decimal, binary,
octal, or hexadecimal) is determined in the same fashion as described in
\fBexpr\fR.  The integer value is stored in the variable,
truncated as required by the size modifier value.
.TP 10
\fBc\fR
A single character is read in and its Unicode value is stored in 
the variable as an integer value.
Initial white space is not skipped in this case, so the input

'\"
'\" 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: string.n,v 1.29 2005/05/23 17:41:00 das Exp $
'\" 
.so man.macros
.TH string n 8.1 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
string \- Manipulate strings
................................................................................
the \fIvarname\fR will contain \-1.
.IP \fBfalse\fR 12
Any of the forms allowed to \fBTcl_GetBoolean\fR where the value is
false.
.IP \fBgraph\fR 12
Any Unicode printing character, except space.
.IP \fBinteger\fR 12
Any of the valid forms for an ordinary integer in Tcl, with optional
surrounding whitespace.  In case of under/overflow in the value, 0 is
returned and the \fIvarname\fR will contain \-1.
.IP \fBlower\fR 12
Any Unicode lower case alphabet character.
.IP \fBprint\fR 12
Any Unicode printing character, including space.
.IP \fBpunct\fR 12
Any Unicode punctuation character.
.IP \fBspace\fR 12

'\"
'\" 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: string.n,v 1.30 2006/04/26 04:41:10 dgp Exp $
'\" 
.so man.macros
.TH string n 8.1 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
string \- Manipulate strings
................................................................................
the \fIvarname\fR will contain \-1.
.IP \fBfalse\fR 12
Any of the forms allowed to \fBTcl_GetBoolean\fR where the value is
false.
.IP \fBgraph\fR 12
Any Unicode printing character, except space.
.IP \fBinteger\fR 12
Any of the valid string formats for a 32-bit integer value in Tcl,
with optional surrounding whitespace.  In case of under/overflow in
the value, 0 is returned and the \fIvarname\fR will contain \-1.
.IP \fBlower\fR 12
Any Unicode lower case alphabet character.
.IP \fBprint\fR 12
Any Unicode printing character, including space.
.IP \fBpunct\fR 12
Any Unicode punctuation character.
.IP \fBspace\fR 12