'\"
'\" 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 1.1.1.1 2007/07/10 15:04:23 duncan 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
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'\"
'\" .BE
'\"	End of box enclosure.
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'\" .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 1.1.1.1 2007/07/10 15:04:23 duncan 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
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.ie !"\\$4"" .TP \\$4
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\&\\$1	\\fI\\$2\\fP	(\\$3)
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\&\\$1	\\fI\\$2\\fP
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\&\\fI\\$1\\fP
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.nr )A 10n
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.\"
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.nr )C \\n()Bu+\\w'(in/out)'u+2n
..
.AS Tcl_Interp Tcl_CreateInterp in/out
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\h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
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'ti 0
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..
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.sp
..
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.LP
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.ft B
..
'\"	# SE - end of list of standard options
.de SE
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.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
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Command-Line Name:	\\fB\\$1\\fR
Database Name:	\\fB\\$2\\fR
Database Class:	\\fB\\$3\\fR
.fi
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.de UL
\\$1\l'|0\(ul'\\$2
..
.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
.SH SYNOPSIS
\fBlindex \fIlist ?index...?\fR
.BE
.SH DESCRIPTION
.PP
.VS 8.4
The \fBlindex\fP command accepts a parameter, \fIlist\fP, which
it treats as a Tcl list. It also accepts zero or more \fIindices\fP into
the list.  The indices may be presented either consecutively on the
command line, or grouped in a
Tcl list and presented as a single argument.
.PP
If no indices are presented, the command takes the form:
.CS
lindex list
.CE
or
.CS
lindex list {}
.CE
In this case, the return value of \fBlindex\fR is simply the value of the
\fIlist\fR parameter.
.PP
When presented with a single index, the \fBlindex\fR command
treats \fIlist\fR as a Tcl list and returns the
.VE
\fIindex\fR'th element from it (0 refers to the first element of the list).
In extracting the element, \fBlindex\fR observes the same rules
concerning braces and quotes and backslashes as the Tcl command
interpreter; however, variable
substitution and command substitution do not occur.
If \fIindex\fR is negative or greater than or equal to the number
of elements in \fIvalue\fR, then an empty
string is returned.
If \fIindex\fR has the value \fBend\fR, it refers to the last element
in the list, and \fBend\-\fIinteger\fR refers to the last element in
the list minus the specified integer offset.
.PP
.VS 8.4
If additional \fIindex\fR arguments are supplied, then each argument is
used in turn to select an element from the previous indexing operation,
allowing the script to select elements from sublists.  The command,
.CS
lindex $a 1 2 3
.CE
or
.CS
lindex $a {1 2 3}
.CE
is synonymous with
.CS
lindex [lindex [lindex $a 1] 2] 3
.CE
.SH EXAMPLES
.CS
\fBlindex\fR {a b c}  \fI=> a b c\fR
\fBlindex\fR {a b c} {} \fI=> a b c\fR
\fBlindex\fR {a b c} 0 \fI=> a\fR
\fBlindex\fR {a b c} 2 \fI=> c\fR
\fBlindex\fR {a b c} end \fI=> c\fR
\fBlindex\fR {a b c} end-1 \fI=> b\fR
\fBlindex\fR {{a b c} {d e f} {g h i}} 2 1 \fI=> h\fR
\fBlindex\fR {{a b c} {d e f} {g h i}} {2 1} \fI=> h\fR
\fBlindex\fR {{{a b} {c d}} {{e f} {g h}}} 1 1 0 \fI=> g\fR
\fBlindex\fR {{{a b} {c d}} {{e f} {g h}}} {1 1 0} \fI=> g\fR
.CE
.VE
.SH "SEE ALSO"
list(n), lappend(n), linsert(n), llength(n), lsearch(n), 
.VS 8.4
lset(n),
.VE
lsort(n),
lrange(n), lreplace(n)

.SH KEYWORDS
element, index, list