man/man1/tclsh.1 - toolchains/skids - Git at Google

 '\"
 '\" 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: tclsh.1,v 1.7 2002/07/23 18:17:12 jenglish Exp $
 '\"
 '\" The definitions below are for supplemental macros used in Tcl/Tk
 '\" manual entries.
 '\"
 '\" .AP type name in/out ?indent?
 '\"	Start paragraph describing an argument to a library procedure.
 '\"	type is type of argument (int, etc.), in/out is either "in", "out",
 '\"	or "in/out" to describe whether procedure reads or modifies arg,
 '\"	and indent is equivalent to second arg of .IP (shouldn't ever be
 '\"	needed;  use .AS below instead)
 '\"
 '\" .AS ?type? ?name?
 '\"	Give maximum sizes of arguments for setting tab stops.  Type and
 '\"	name are examples of largest possible arguments that will be passed
 '\"	to .AP later.  If args are omitted, default tab stops are used.
 '\"
 '\" .BS
 '\"	Start box enclosure.  From here until next .BE, everything will be
 '\"	enclosed in one large box.
 '\"
 '\" .BE
 '\"	End of box enclosure.
 '\"
 '\" .CS
 '\"	Begin code excerpt.
 '\"
 '\" .CE
 '\"	End code excerpt.
 '\"
 '\" .VS ?version? ?br?
 '\"	Begin vertical sidebar, for use in marking newly-changed parts
 '\"	of man pages.  The first argument is ignored and used for recording
 '\"	the version when the .VS was added, so that the sidebars can be
 '\"	found and removed when they reach a certain age.  If another argument
 '\"	is present, then a line break is forced before starting the sidebar.
 '\"
 '\" .VE
 '\"	End of vertical sidebar.
 '\"
 '\" .DS
 '\"	Begin an indented unfilled display.
 '\"
 '\" .DE
 '\"	End of indented unfilled display.
 '\"
 '\" .SO
 '\"	Start of list of standard options for a Tk widget.  The
 '\"	options follow on successive lines, in four columns separated
 '\"	by tabs.
 '\"
 '\" .SE
 '\"	End of list of standard options for a Tk widget.
 '\"
 '\" .OP cmdName dbName dbClass
 '\"	Start of description of a specific option.  cmdName gives the
 '\"	option's name as specified in the class command, dbName gives
 '\"	the option's name in the option database, and dbClass gives
 '\"	the option's class in the option database.
 '\"
 '\" .UL arg1 arg2
 '\"	Print arg1 underlined, then print arg2 normally.
 '\"
 '\" RCS: @(#) $Id: man.macros,v 1.4 2000/08/25 06:18:32 ericm Exp $
 '\"
 '\"	# Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
 .if t .wh -1.3i ^B
 .nr ^l \n(.l
 .ad b
 '\"	# Start an argument description
 .de AP
 .ie !"\\$4"" .TP \\$4
 .el \{\
 .   ie !"\\$2"" .TP \\n()Cu
 .   el          .TP 15
 .\}
 .ta \\n()Au \\n()Bu
 .ie !"\\$3"" \{\
 \&\\$1	\\fI\\$2\\fP	(\\$3)
 .\".b
 .\}
 .el \{\
 .br
 .ie !"\\$2"" \{\
 \&\\$1	\\fI\\$2\\fP
 .\}
 .el \{\
 \&\\fI\\$1\\fP
 .\}
 .\}
 ..
 '\"	# define tabbing values for .AP
 .de AS
 .nr )A 10n
 .if !"\\$1"" .nr )A \\w'\\$1'u+3n
 .nr )B \\n()Au+15n
 .\"
 .if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n
 .nr )C \\n()Bu+\\w'(in/out)'u+2n
 ..
 .AS Tcl_Interp Tcl_CreateInterp in/out
 '\"	# BS - start boxed text
 '\"	# ^y = starting y location
 '\"	# ^b = 1
 .de BS
 .br
 .mk ^y
 .nr ^b 1u
 .if n .nf
 .if n .ti 0
 .if n \l'\\n(.lu\(ul'
 .if n .fi
 ..
 '\"	# BE - end boxed text (draw box now)
 .de BE
 .nf
 .ti 0
 .mk ^t
 .ie n \l'\\n(^lu\(ul'
 .el \{\
 .\"	Draw four-sided box normally, but don't draw top of
 .\"	box if the box started on an earlier page.
 .ie !\\n(^b-1 \{\
 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
 .\}
 .el \}\
 \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
 .\}
 .\}
 .fi
 .br
 .nr ^b 0
 ..
 '\"	# VS - start vertical sidebar
 '\"	# ^Y = starting y location
 '\"	# ^v = 1 (for troff;  for nroff this doesn't matter)
 .de VS
 .if !"\\$2"" .br
 .mk ^Y
 .ie n 'mc \s12\(br\s0
 .el .nr ^v 1u
 ..
 '\"	# VE - end of vertical sidebar
 .de VE
 .ie n 'mc
 .el \{\
 .ev 2
 .nf
 .ti 0
 .mk ^t
 \h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n'
 .sp -1
 .fi
 .ev
 .\}
 .nr ^v 0
 ..
 '\"	# Special macro to handle page bottom:  finish off current
 '\"	# box/sidebar if in box/sidebar mode, then invoked standard
 '\"	# page bottom macro.
 .de ^B
 .ev 2
 'ti 0
 'nf
 .mk ^t
 .if \\n(^b \{\
 .\"	Draw three-sided box if this is the box's first page,
 .\"	draw two sides but no top otherwise.
 .ie !\\n(^b-1 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c
 .el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c
 .\}
 .if \\n(^v \{\
 .nr ^x \\n(^tu+1v-\\n(^Yu
 \kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c
 .\}
 .bp
 'fi
 .ev
 .if \\n(^b \{\
 .mk ^y
 .nr ^b 2
 .\}
 .if \\n(^v \{\
 .mk ^Y
 .\}
 ..
 '\"	# DS - begin display
 .de DS
 .RS
 .nf
 .sp
 ..
 '\"	# DE - end display
 .de DE
 .fi
 .RE
 .sp
 ..
 '\"	# SO - start of list of standard options
 .de SO
 .SH "STANDARD OPTIONS"
 .LP
 .nf
 .ta 5.5c 11c
 .ft B
 ..
 '\"	# SE - end of list of standard options
 .de SE
 .fi
 .ft R
 .LP
 See the \\fBoptions\\fR manual entry for details on the standard options.
 ..
 '\"	# OP - start of full description for a single option
 .de OP
 .LP
 .nf
 .ta 4c
 Command-Line Name:	\\fB\\$1\\fR
 Database Name:	\\fB\\$2\\fR
 Database Class:	\\fB\\$3\\fR
 .fi
 .IP
 ..
 '\"	# CS - begin code excerpt
 .de CS
 .RS
 .nf
 .ta .25i .5i .75i 1i
 ..
 '\"	# CE - end code excerpt
 .de CE
 .fi
 .RE
 ..
 .de UL
 \\$1\l'|0\(ul'\\$2
 ..
 .TH tclsh 1 "" Tcl "Tcl Applications"
 .BS
 '\" Note:  do not modify the .SH NAME line immediately below!
 .SH NAME
 tclsh \- Simple shell containing Tcl interpreter
 .SH SYNOPSIS
 \fBtclsh\fR ?\fIfileName arg arg ...\fR?
 .BE

 .SH DESCRIPTION
 .PP
 \fBTclsh\fR is a shell-like application that reads Tcl commands
 from its standard input or from a file and evaluates them.
 If invoked with no arguments then it runs interactively, reading
 Tcl commands from standard input and printing command results and
 error messages to standard output.
 It runs until the \fBexit\fR command is invoked or until it
 reaches end-of-file on its standard input.
 If there exists a file \fB.tclshrc\fR (or \fBtclshrc.tcl\fR on
 the Windows platforms) in the home directory of
 the user, \fBtclsh\fR evaluates the file as a Tcl script
 just before reading the first command from standard input.

 .SH "SCRIPT FILES"
 .PP
 If \fBtclsh\fR is invoked with arguments then the first argument
 is the name of a script file and any additional arguments
 are made available to the script as variables (see below).
 Instead of reading commands from standard input \fBtclsh\fR will
 read Tcl commands from the named file;  \fBtclsh\fR will exit
 when it reaches the end of the file.
 There is no automatic evaluation of \fB.tclshrc\fR in this
 case, but the script file can always \fBsource\fR it if desired.
 .PP
 If you create a Tcl script in a file whose first line is
 .CS
 \fB#!/usr/local/bin/tclsh\fR
 .CE
 then you can invoke the script file directly from your shell if
 you mark the file as executable.
 This assumes that \fBtclsh\fR has been installed in the default
 location in /usr/local/bin;  if it's installed somewhere else
 then you'll have to modify the above line to match.
 Many UNIX systems do not allow the \fB#!\fR line to exceed about
 30 characters in length, so be sure that the \fBtclsh\fR
 executable can be accessed with a short file name.
 .PP
 An even better approach is to start your script files with the
 following three lines:
 .CS
 \fB#!/bin/sh
 # the next line restarts using tclsh \e
 exec tclsh "$0" "$@"\fR
 .CE
 This approach has three advantages over the approach in the previous
 paragraph.  First, the location of the \fBtclsh\fR binary doesn't have
 to be hard-wired into the script:  it can be anywhere in your shell
 search path.  Second, it gets around the 30-character file name limit
 in the previous approach.
 Third, this approach will work even if \fBtclsh\fR is
 itself a shell script (this is done on some systems in order to
 handle multiple architectures or operating systems:  the \fBtclsh\fR
 script selects one of several binaries to run).  The three lines
 cause both \fBsh\fR and \fBtclsh\fR to process the script, but the
 \fBexec\fR is only executed by \fBsh\fR.
 \fBsh\fR processes the script first;  it treats the second
 line as a comment and executes the third line.
 The \fBexec\fR statement cause the shell to stop processing and
 instead to start up \fBtclsh\fR to reprocess the entire script.
 When \fBtclsh\fR starts up, it treats all three lines as comments,
 since the backslash at the end of the second line causes the third
 line to be treated as part of the comment on the second line.
 .PP
 .VS
 You should note that it is also common practise to install tclsh with
 its version number as part of the name.  This has the advantage of
 allowing multiple versions of Tcl to exist on the same system at once,
 but also the disadvantage of making it harder to write scripts that
 start up uniformly across different versions of Tcl.
 .VE

 .SH "VARIABLES"
 .PP
 \fBTclsh\fR sets the following Tcl variables:
 .TP 15
 \fBargc\fR
 Contains a count of the number of \fIarg\fR arguments (0 if none),
 not including the name of the script file.
 .TP 15
 \fBargv\fR
 Contains a Tcl list whose elements are the \fIarg\fR arguments,
 in order, or an empty string if there are no \fIarg\fR arguments.
 .TP 15
 \fBargv0\fR
 Contains \fIfileName\fR if it was specified.
 Otherwise, contains the name by which \fBtclsh\fR was invoked.
 .TP 15
 \fBtcl_interactive\fR
 Contains 1 if \fBtclsh\fR is running interactively (no
 \fIfileName\fR was specified and standard input is a terminal-like
 device), 0 otherwise.

 .SH PROMPTS
 .PP
 When \fBtclsh\fR is invoked interactively it normally prompts for each
 command with ``\fB% \fR''.  You can change the prompt by setting the
 variables \fBtcl_prompt1\fR and \fBtcl_prompt2\fR.  If variable
 \fBtcl_prompt1\fR exists then it must consist of a Tcl script
 to output a prompt;  instead of outputting a prompt \fBtclsh\fR
 will evaluate the script in \fBtcl_prompt1\fR.
 The variable \fBtcl_prompt2\fR is used in a similar way when
 a newline is typed but the current command isn't yet complete;
 if \fBtcl_prompt2\fR isn't set then no prompt is output for
 incomplete commands.

 .SH "STANDARD CHANNELS"
 .PP
 See \fBTcl_StandardChannels\fR for more explanations.

 .SH "SEE ALSO"
 fconfigure(n), tclvars(n)

 .SH KEYWORDS
 argument, interpreter, prompt, script file, shell
	'\"
	'\" 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: tclsh.1,v 1.7 2002/07/23 18:17:12 jenglish Exp $
	'\"
	'\" The definitions below are for supplemental macros used in Tcl/Tk
	'\" manual entries.
	'\"
	'\" .AP type name in/out ?indent?
	'\" Start paragraph describing an argument to a library procedure.
	'\" type is type of argument (int, etc.), in/out is either "in", "out",
	'\" or "in/out" to describe whether procedure reads or modifies arg,
	'\" and indent is equivalent to second arg of .IP (shouldn't ever be
	'\" needed; use .AS below instead)
	'\"
	'\" .AS ?type? ?name?
	'\" Give maximum sizes of arguments for setting tab stops. Type and
	'\" name are examples of largest possible arguments that will be passed
	'\" to .AP later. If args are omitted, default tab stops are used.
	'\"
	'\" .BS
	'\" Start box enclosure. From here until next .BE, everything will be
	'\" enclosed in one large box.
	'\"
	'\" .BE
	'\" End of box enclosure.
	'\"
	'\" .CS
	'\" Begin code excerpt.
	'\"
	'\" .CE
	'\" End code excerpt.
	'\"
	'\" .VS ?version? ?br?
	'\" Begin vertical sidebar, for use in marking newly-changed parts
	'\" of man pages. The first argument is ignored and used for recording
	'\" the version when the .VS was added, so that the sidebars can be
	'\" found and removed when they reach a certain age. If another argument
	'\" is present, then a line break is forced before starting the sidebar.
	'\"
	'\" .VE
	'\" End of vertical sidebar.
	'\"
	'\" .DS
	'\" Begin an indented unfilled display.
	'\"
	'\" .DE
	'\" End of indented unfilled display.
	'\"
	'\" .SO
	'\" Start of list of standard options for a Tk widget. The
	'\" options follow on successive lines, in four columns separated
	'\" by tabs.
	'\"
	'\" .SE
	'\" End of list of standard options for a Tk widget.
	'\"
	'\" .OP cmdName dbName dbClass
	'\" Start of description of a specific option. cmdName gives the
	'\" option's name as specified in the class command, dbName gives
	'\" the option's name in the option database, and dbClass gives
	'\" the option's class in the option database.
	'\"
	'\" .UL arg1 arg2
	'\" Print arg1 underlined, then print arg2 normally.
	'\"
	'\" RCS: @(#) $Id: man.macros,v 1.4 2000/08/25 06:18:32 ericm Exp $
	'\"
	'\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
	.if t .wh -1.3i ^B
	.nr ^l \n(.l
	.ad b
	'\" # Start an argument description
	.de AP
	.ie !"\\$4"" .TP \\$4
	.el \{\
	. ie !"\\$2"" .TP \\n()Cu
	. el .TP 15
	.\}
	.ta \\n()Au \\n()Bu
	.ie !"\\$3"" \{\
	\&\\$1 \\fI\\$2\\fP (\\$3)
	.\".b
	.\}
	.el \{\
	.br
	.ie !"\\$2"" \{\
	\&\\$1 \\fI\\$2\\fP
	.\}
	.el \{\
	\&\\fI\\$1\\fP
	.\}
	.\}
	..
	'\" # define tabbing values for .AP
	.de AS
	.nr )A 10n
	.if !"\\$1"" .nr )A \\w'\\$1'u+3n
	.nr )B \\n()Au+15n
	.\"
	.if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n
	.nr )C \\n()Bu+\\w'(in/out)'u+2n
	..
	.AS Tcl_Interp Tcl_CreateInterp in/out
	'\" # BS - start boxed text
	'\" # ^y = starting y location
	'\" # ^b = 1
	.de BS
	.br
	.mk ^y
	.nr ^b 1u
	.if n .nf
	.if n .ti 0
	.if n \l'\\n(.lu\(ul'
	.if n .fi
	..
	'\" # BE - end boxed text (draw box now)
	.de BE
	.nf
	.ti 0
	.mk ^t
	.ie n \l'\\n(^lu\(ul'
	.el \{\
	.\" Draw four-sided box normally, but don't draw top of
	.\" box if the box started on an earlier page.
	.ie !\\n(^b-1 \{\
	\h'-1.5n'\L'\|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'\|0u-1.5n\(ul'
	.\}
	.el \}\
	\h'-1.5n'\L'\|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'\|0u-1.5n\(ul'
	.\}
	.\}
	.fi
	.br
	.nr ^b 0
	..
	'\" # VS - start vertical sidebar
	'\" # ^Y = starting y location
	'\" # ^v = 1 (for troff; for nroff this doesn't matter)
	.de VS
	.if !"\\$2"" .br
	.mk ^Y
	.ie n 'mc \s12\(br\s0
	.el .nr ^v 1u
	..
	'\" # VE - end of vertical sidebar
	.de VE
	.ie n 'mc
	.el \{\
	.ev 2
	.nf
	.ti 0
	.mk ^t
	\h'\|\\n(^lu+3n'\L'\|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-\|\\n(^lu+3n'
	.sp -1
	.fi
	.ev
	.\}
	.nr ^v 0
	..
	'\" # Special macro to handle page bottom: finish off current
	'\" # box/sidebar if in box/sidebar mode, then invoked standard
	'\" # page bottom macro.
	.de ^B
	.ev 2
	'ti 0
	'nf
	.mk ^t
	.if \\n(^b \{\
	.\" Draw three-sided box if this is the box's first page,
	.\" draw two sides but no top otherwise.
	.ie !\\n(^b-1 \h'-1.5n'\L'\|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'\|0u'\c
	.el \h'-1.5n'\L'\|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'\|0u'\c
	.\}
	.if \\n(^v \{\
	.nr ^x \\n(^tu+1v-\\n(^Yu
	\kx\h'-\\nxu'\h'\|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'\|0u'\c
	.\}
	.bp
	'fi
	.ev
	.if \\n(^b \{\
	.mk ^y
	.nr ^b 2
	.\}
	.if \\n(^v \{\
	.mk ^Y
	.\}
	..
	'\" # DS - begin display
	.de DS
	.RS
	.nf
	.sp
	..
	'\" # DE - end display
	.de DE
	.fi
	.RE
	.sp
	..
	'\" # SO - start of list of standard options
	.de SO
	.SH "STANDARD OPTIONS"
	.LP
	.nf
	.ta 5.5c 11c
	.ft B
	..
	'\" # SE - end of list of standard options
	.de SE
	.fi
	.ft R
	.LP
	See the \\fBoptions\\fR manual entry for details on the standard options.
	..
	'\" # OP - start of full description for a single option
	.de OP
	.LP
	.nf
	.ta 4c
	Command-Line Name: \\fB\\$1\\fR
	Database Name: \\fB\\$2\\fR
	Database Class: \\fB\\$3\\fR
	.fi
	.IP
	..
	'\" # CS - begin code excerpt
	.de CS
	.RS
	.nf
	.ta .25i .5i .75i 1i
	..
	'\" # CE - end code excerpt
	.de CE
	.fi
	.RE
	..
	.de UL
	\\$1\l'\|0\(ul'\\$2
	..
	.TH tclsh 1 "" Tcl "Tcl Applications"
	.BS
	'\" Note: do not modify the .SH NAME line immediately below!
	.SH NAME
	tclsh \- Simple shell containing Tcl interpreter
	.SH SYNOPSIS
	\fBtclsh\fR ?\fIfileName arg arg ...\fR?
	.BE

	.SH DESCRIPTION
	.PP
	\fBTclsh\fR is a shell-like application that reads Tcl commands
	from its standard input or from a file and evaluates them.
	If invoked with no arguments then it runs interactively, reading
	Tcl commands from standard input and printing command results and
	error messages to standard output.
	It runs until the \fBexit\fR command is invoked or until it
	reaches end-of-file on its standard input.
	If there exists a file \fB.tclshrc\fR (or \fBtclshrc.tcl\fR on
	the Windows platforms) in the home directory of
	the user, \fBtclsh\fR evaluates the file as a Tcl script
	just before reading the first command from standard input.

	.SH "SCRIPT FILES"
	.PP
	If \fBtclsh\fR is invoked with arguments then the first argument
	is the name of a script file and any additional arguments
	are made available to the script as variables (see below).
	Instead of reading commands from standard input \fBtclsh\fR will
	read Tcl commands from the named file; \fBtclsh\fR will exit
	when it reaches the end of the file.
	There is no automatic evaluation of \fB.tclshrc\fR in this
	case, but the script file can always \fBsource\fR it if desired.
	.PP
	If you create a Tcl script in a file whose first line is
	.CS
	\fB#!/usr/local/bin/tclsh\fR
	.CE
	then you can invoke the script file directly from your shell if
	you mark the file as executable.
	This assumes that \fBtclsh\fR has been installed in the default
	location in /usr/local/bin; if it's installed somewhere else
	then you'll have to modify the above line to match.
	Many UNIX systems do not allow the \fB#!\fR line to exceed about
	30 characters in length, so be sure that the \fBtclsh\fR
	executable can be accessed with a short file name.
	.PP
	An even better approach is to start your script files with the
	following three lines:
	.CS
	\fB#!/bin/sh
	# the next line restarts using tclsh \e
	exec tclsh "$0" "$@"\fR
	.CE
	This approach has three advantages over the approach in the previous
	paragraph. First, the location of the \fBtclsh\fR binary doesn't have
	to be hard-wired into the script: it can be anywhere in your shell
	search path. Second, it gets around the 30-character file name limit
	in the previous approach.
	Third, this approach will work even if \fBtclsh\fR is
	itself a shell script (this is done on some systems in order to
	handle multiple architectures or operating systems: the \fBtclsh\fR
	script selects one of several binaries to run). The three lines
	cause both \fBsh\fR and \fBtclsh\fR to process the script, but the
	\fBexec\fR is only executed by \fBsh\fR.
	\fBsh\fR processes the script first; it treats the second
	line as a comment and executes the third line.
	The \fBexec\fR statement cause the shell to stop processing and
	instead to start up \fBtclsh\fR to reprocess the entire script.
	When \fBtclsh\fR starts up, it treats all three lines as comments,
	since the backslash at the end of the second line causes the third
	line to be treated as part of the comment on the second line.
	.PP
	.VS
	You should note that it is also common practise to install tclsh with
	its version number as part of the name. This has the advantage of
	allowing multiple versions of Tcl to exist on the same system at once,
	but also the disadvantage of making it harder to write scripts that
	start up uniformly across different versions of Tcl.
	.VE

	.SH "VARIABLES"
	.PP
	\fBTclsh\fR sets the following Tcl variables:
	.TP 15
	\fBargc\fR
	Contains a count of the number of \fIarg\fR arguments (0 if none),
	not including the name of the script file.
	.TP 15
	\fBargv\fR
	Contains a Tcl list whose elements are the \fIarg\fR arguments,
	in order, or an empty string if there are no \fIarg\fR arguments.
	.TP 15
	\fBargv0\fR
	Contains \fIfileName\fR if it was specified.
	Otherwise, contains the name by which \fBtclsh\fR was invoked.
	.TP 15
	\fBtcl_interactive\fR
	Contains 1 if \fBtclsh\fR is running interactively (no
	\fIfileName\fR was specified and standard input is a terminal-like
	device), 0 otherwise.

	.SH PROMPTS
	.PP
	When \fBtclsh\fR is invoked interactively it normally prompts for each
	command with ``\fB% \fR''. You can change the prompt by setting the
	variables \fBtcl_prompt1\fR and \fBtcl_prompt2\fR. If variable
	\fBtcl_prompt1\fR exists then it must consist of a Tcl script
	to output a prompt; instead of outputting a prompt \fBtclsh\fR
	will evaluate the script in \fBtcl_prompt1\fR.
	The variable \fBtcl_prompt2\fR is used in a similar way when
	a newline is typed but the current command isn't yet complete;
	if \fBtcl_prompt2\fR isn't set then no prompt is output for
	incomplete commands.

	.SH "STANDARD CHANNELS"
	.PP
	See \fBTcl_StandardChannels\fR for more explanations.

	.SH "SEE ALSO"
	fconfigure(n), tclvars(n)

	.SH KEYWORDS
	argument, interpreter, prompt, script file, shell