Tcl Source Code

input or output. \fInewSize\fR must be a number of no more than one
million, allowing buffers of up to one million bytes in size.
.\" OPTION: -encoding
.TP
\fB\-encoding\fR \fIname\fR
.
This option is used to specify the encoding of the channel as one of
the named encodings returned by \fBencoding names\fR, so that the
data can be converted to and from
Unicode for use in Tcl.  For instance, in order for Tcl to read
characters from a Japanese file in \fBshiftjis\fR and properly process
and display the contents, the encoding would be set to \fBshiftjis\fR.
Thereafter, when reading from the channel, the bytes in the Japanese
file would be converted to Unicode as they are read.  Writing is also
supported \- as Tcl strings are written to the channel they will
automatically be converted to the specified encoding on output.
.RS
.PP
If a file contains pure binary data (for instance, a JPEG image), the
encoding for the channel should be configured to be \fBiso8859-1\fR.  Tcl
will then assign no interpretation to the data in the file and simply
read or write raw bytes.  The Tcl \fBbinary\fR command can be used to
manipulate this byte-oriented data.  It is usually better to set the
\fB\-translation\fR option to \fBbinary\fR when you want to transfer
binary data, as this turns off the other automatic interpretations of
the bytes in the stream as well.
.PP

.PP
If the encoding profile \fBstrict\fR is in effect for the channel, the command
will raise an exception with the POSIX error code \fBEILSEQ\fR if any encoding
errors are encountered in the channel input data. The file pointer remains
unchanged and it is possible to introspect, and in some cases recover, by
changing the encoding in use. See \fBENCODING ERROR EXAMPLES\fR later.
.RE
.\" METHOD: isbinary
.TP
\fBchan isbinary \fIchannel\fR
.
Test whether the channel called \fIchannel\fR is a binary channel,
returning 1 if it is and, and 0 otherwise. A binary channel is
a channel with iso8859-1 encoding, -eofchar set to {} and
-translation set to lf.
.\" METHOD: names
.TP
\fBchan names\fR ?\fIpattern\fR?
.
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.

    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * TclChanIsBinary --
 *
 *	Returns 1 if the channel is a binary channel, 0 otherwise.
 *
 * Results:
 *	1 or 0, always.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
TclChanIsBinary(
    Tcl_Channel chan)		/* Does this channel have EOF? */
{
    ChannelState *statePtr = ((Channel *) chan)->state;
				/* State of real channel structure. */

    return ((statePtr->encoding == GetBinaryEncoding()) && !statePtr->inEofChar
	    && (!GotFlag(statePtr, TCL_READABLE) || (statePtr->inputTranslation == TCL_TRANSLATE_LF))
	    && (!GotFlag(statePtr, TCL_WRITABLE) || (statePtr->outputTranslation == TCL_TRANSLATE_LF)));
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_Eof --
 *
 *	Returns 1 if the channel is at EOF, 0 otherwise.
 *
 * Results:
 *	1 or 0, always.
 *

	}
	Tcl_SetChannelBufferSize(chan, newBufferSize);
	return TCL_OK;
    } else if (HaveOpt(2, "-encoding")) {
	Tcl_Encoding encoding;
	int profile;

	if ((newValue[0] == '\0') || !strcmp(newValue, "binary")) {
	    Tcl_SetObjResult(interp, Tcl_ObjPrintf("unknown encoding \"%s\": No longer supported.\n"
		    "\tplease use either \"-translation binary\" or \"-encoding iso8859-1\"", newValue));
	    return TCL_ERROR;
	} else {
	    encoding = Tcl_GetEncoding(interp, newValue);
	    if (encoding == NULL) {
		return TCL_ERROR;
	    }
	}

    if (TclGetChannelFromObj(interp, objv[1], &chan, NULL, 0) != TCL_OK) {
	return TCL_ERROR;
    }

    Tcl_SetObjResult(interp, Tcl_NewBooleanObj(Tcl_Eof(chan)));
    return TCL_OK;
}

/*
 *---------------------------------------------------------------------------
 *
 * ChanIsBinaryCmd --
 *
 *	This function is invoked to process the Tcl "chan isbinary" command. See the
 *	user documentation for details on what it does.
 *
 * Results:
 *	A standard Tcl result.
 *
 * Side effects:
 *	Sets interp's result to boolean true or false depending on whether the
 *	specified channel is a binary channel.
 *
 *---------------------------------------------------------------------------
 */

static int
ChanIsBinaryCmd(
    TCL_UNUSED(void *),
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Tcl_Channel chan;

    if (objc != 2) {
	Tcl_WrongNumArgs(interp, 1, objv, "channel");
	return TCL_ERROR;
    }

    if (TclGetChannelFromObj(interp, objv[1], &chan, NULL, 0) != TCL_OK) {
	return TCL_ERROR;
    }

    Tcl_SetObjResult(interp, Tcl_NewBooleanObj(TclChanIsBinary(chan)));
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_ExecObjCmd --
 *
 *	This function is invoked to process the "exec" Tcl command. See the

	{"close",	Tcl_CloseObjCmd,	TclCompileBasic1Or2ArgCmd, NULL, NULL, 0},
	{"copy",	Tcl_FcopyObjCmd,	NULL, NULL, NULL, 0},
	{"create",	TclChanCreateObjCmd,	TclCompileBasic2ArgCmd, NULL, NULL, 0},		/* TIP #219 */
	{"eof",		Tcl_EofObjCmd,		TclCompileBasic1ArgCmd, NULL, NULL, 0},
	{"event",	Tcl_FileEventObjCmd,	TclCompileBasic2Or3ArgCmd, NULL, NULL, 0},
	{"flush",	Tcl_FlushObjCmd,	TclCompileBasic1ArgCmd, NULL, NULL, 0},
	{"gets",	Tcl_GetsObjCmd,		TclCompileBasic1Or2ArgCmd, NULL, NULL, 0},
	{"isbinary",	ChanIsBinaryCmd,	TclCompileBasic1ArgCmd, NULL, NULL, 0},
	{"names",	TclChannelNamesCmd,	TclCompileBasic0Or1ArgCmd, NULL, NULL, 0},
	{"pending",	ChanPendingObjCmd,	TclCompileBasic2ArgCmd, NULL, NULL, 0},		/* TIP #287 */
	{"pipe",	ChanPipeObjCmd,		TclCompileBasic0ArgCmd, NULL, NULL, 0},		/* TIP #304 */
	{"pop",		TclChanPopObjCmd,	TclCompileBasic1ArgCmd, NULL, NULL, 0},		/* TIP #230 */
	{"postevent",	TclChanPostEventObjCmd,	TclCompileBasic2ArgCmd, NULL, NULL, 0},	/* TIP #219 */
	{"push",	TclChanPushObjCmd,	TclCompileBasic2ArgCmd, NULL, NULL, 0},		/* TIP #230 */
	{"puts",	Tcl_PutsObjCmd,		NULL, NULL, NULL, 0},

MODULE_SCOPE int	TclChannelGetBlockingMode(Tcl_Channel chan);
MODULE_SCOPE int	TclCheckArrayTraces(Tcl_Interp *interp, Var *varPtr,
			    Var *arrayPtr, Tcl_Obj *name, int index);
MODULE_SCOPE int	TclCheckEmptyString(Tcl_Obj *objPtr);
MODULE_SCOPE int	TclChanCaughtErrorBypass(Tcl_Interp *interp,
			    Tcl_Channel chan);
MODULE_SCOPE Tcl_ObjCmdProc TclChannelNamesCmd;
MODULE_SCOPE int TclChanIsBinary(Tcl_Channel chan);
MODULE_SCOPE Tcl_NRPostProc TclClearRootEnsemble;
MODULE_SCOPE int	TclCompareTwoNumbers(Tcl_Obj *valuePtr,
			    Tcl_Obj *value2Ptr);
MODULE_SCOPE ContLineLoc *TclContinuationsEnter(Tcl_Obj *objPtr, Tcl_Size num,
			    Tcl_Size *loc);
MODULE_SCOPE void	TclContinuationsEnterDerived(Tcl_Obj *objPtr,
			    Tcl_Size start, Tcl_Size *clNext);

} -body {
    seek $f 0
    puts -nonewline $f 12345
    seek $f 0
    chan truncate $f 2
    read $f
} -result 12 -cleanup {
    catch {close $f}
    catch {removeFile $file}
}
test chan-15.3 {chan command: isbinary subcommand} -setup {
    set file [makeFile {} testIsBinary]
    set f [open $file w+]
    fconfigure $f -translation binary
} -body {
    chan isbinary $f
} -result 1 -cleanup {
    catch {close $f}
    catch {removeFile $file}
}

# TIP 287: chan pending
test chan-16.1 {chan command: pending subcommand} -body {
    chan pending

catch [list package require -exact tcl::test [info patchlevel]]

testConstraint testchmod       [llength [info commands testchmod]]
testConstraint testsetplatform [llength [info commands testsetplatform]]
testConstraint testvolumetype  [llength [info commands testvolumetype]]
testConstraint testbytestring [llength [info commands testbytestring]]
testConstraint time64bit [expr {
    ([llength [info command testsize]] ?
	[testsize st_mtime] : $::tcl_platform(pointerSize)) >= 8
}]
testConstraint linkDirectory [expr {
    ![testConstraint win] ||
    ($::tcl_platform(osVersion) >= 5.0
     && [lindex [file system [temporaryDirectory]] 1] eq "NTFS")
}]