'\" '\" 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 $ '\" .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 .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