2 '\" Copyright (c) 1993 The Regents of the University of California.
3 '\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
4 '\" Copyright (c) 2001 by Kevin B. Kenny <kennykb@acm.org>. All rights reserved.
6 '\" See the file "license.terms" for information on usage and redistribution
7 '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
9 .TH lindex n 8.4 Tcl "Tcl Built-In Commands"
10 .\" The -*- nroff -*- definitions below are for supplemental macros used
11 .\" in Tcl/Tk manual entries.
13 .\" .AP type name in/out ?indent?
14 .\" Start paragraph describing an argument to a library procedure.
15 .\" type is type of argument (int, etc.), in/out is either "in", "out",
16 .\" or "in/out" to describe whether procedure reads or modifies arg,
17 .\" and indent is equivalent to second arg of .IP (shouldn't ever be
18 .\" needed; use .AS below instead)
21 .\" Give maximum sizes of arguments for setting tab stops. Type and
22 .\" name are examples of largest possible arguments that will be passed
23 .\" to .AP later. If args are omitted, default tab stops are used.
26 .\" Start box enclosure. From here until next .BE, everything will be
27 .\" enclosed in one large box.
30 .\" End of box enclosure.
33 .\" Begin code excerpt.
38 .\" .VS ?version? ?br?
39 .\" Begin vertical sidebar, for use in marking newly-changed parts
40 .\" of man pages. The first argument is ignored and used for recording
41 .\" the version when the .VS was added, so that the sidebars can be
42 .\" found and removed when they reach a certain age. If another argument
43 .\" is present, then a line break is forced before starting the sidebar.
46 .\" End of vertical sidebar.
49 .\" Begin an indented unfilled display.
52 .\" End of indented unfilled display.
55 .\" Start of list of standard options for a Tk widget. The manpage
56 .\" argument defines where to look up the standard options; if
57 .\" omitted, defaults to "options". The options follow on successive
58 .\" lines, in three columns separated by tabs.
61 .\" End of list of standard options for a Tk widget.
63 .\" .OP cmdName dbName dbClass
64 .\" Start of description of a specific option. cmdName gives the
65 .\" option's name as specified in the class command, dbName gives
66 .\" the option's name in the option database, and dbClass gives
67 .\" the option's class in the option database.
70 .\" Print arg1 underlined, then print arg2 normally.
73 .\" Print arg1 in quotes, then arg2 normally (for trailing punctuation).
76 .\" Print an open parenthesis, arg1 in quotes, then arg2 normally
77 .\" (for trailing punctuation) and then a closing parenthesis.
79 .\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
83 .\" # Start an argument description
87 . ie !"\\$2"" .TP \\n()Cu
92 \&\\$1 \\fI\\$2\\fP (\\$3)
105 .\" # define tabbing values for .AP
108 .if !"\\$1"" .nr )A \\w'\\$1'u+3n
111 .if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n
112 .nr )C \\n()Bu+\\w'(in/out)'u+2n
114 .AS Tcl_Interp Tcl_CreateInterp in/out
115 .\" # BS - start boxed text
116 .\" # ^y = starting y location
124 .if n \l'\\n(.lu\(ul'
127 .\" # BE - end boxed text (draw box now)
132 .ie n \l'\\n(^lu\(ul'
134 .\" Draw four-sided box normally, but don't draw top of
135 .\" box if the box started on an earlier page.
137 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
140 \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
147 .\" # VS - start vertical sidebar
148 .\" # ^Y = starting y location
149 .\" # ^v = 1 (for troff; for nroff this doesn't matter)
153 .ie n 'mc \s12\(br\s0
156 .\" # VE - end of vertical sidebar
164 \h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n'
171 .\" # Special macro to handle page bottom: finish off current
172 .\" # box/sidebar if in box/sidebar mode, then invoked standard
173 .\" # page bottom macro.
180 .\" Draw three-sided box if this is the box's first page,
181 .\" draw two sides but no top otherwise.
182 .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
183 .el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c
186 .nr ^x \\n(^tu+1v-\\n(^Yu
187 \kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c
200 .\" # DS - begin display
206 .\" # DE - end display
212 .\" # SO - start of list of standard options
214 'ie '\\$1'' .ds So \\fBoptions\\fR
215 'el .ds So \\fB\\$1\\fR
216 .SH "STANDARD OPTIONS"
222 .\" # SE - end of list of standard options
227 See the \\*(So manual entry for details on the standard options.
229 .\" # OP - start of full description for a single option
234 Command-Line Name: \\fB\\$1\\fR
235 Database Name: \\fB\\$2\\fR
236 Database Class: \\fB\\$3\\fR
240 .\" # CS - begin code excerpt
246 .\" # CE - end code excerpt
251 .\" # UL - underline word
255 .\" # QW - apply quotation marks to word
257 .ie '\\*(lq'"' ``\\$1''\\$2
258 .\"" fix emacs highlighting
259 .el \\*(lq\\$1\\*(rq\\$2
261 .\" # PQ - apply parens and quotation marks to word
263 .ie '\\*(lq'"' (``\\$1''\\$2)\\$3
264 .\"" fix emacs highlighting
265 .el (\\*(lq\\$1\\*(rq\\$2)\\$3
267 .\" # QR - quoted range
269 .ie '\\*(lq'"' ``\\$1''\\-``\\$2''\\$3
270 .\"" fix emacs highlighting
271 .el \\*(lq\\$1\\*(rq\\-\\*(lq\\$2\\*(rq\\$3
273 .\" # MT - "empty" string
278 '\" Note: do not modify the .SH NAME line immediately below!
280 lindex \- Retrieve an element from a list
282 \fBlindex \fIlist ?index ...?\fR
286 The \fBlindex\fR command accepts a parameter, \fIlist\fR, which
287 it treats as a Tcl list. It also accepts zero or more \fIindices\fR into
288 the list. The indices may be presented either consecutively on the
289 command line, or grouped in a
290 Tcl list and presented as a single argument.
292 If no indices are presented, the command takes the form:
301 \fBlindex \fIlist\fR {}
304 In this case, the return value of \fBlindex\fR is simply the value of the
305 \fIlist\fR parameter.
307 When presented with a single index, the \fBlindex\fR command
308 treats \fIlist\fR as a Tcl list and returns the
309 \fIindex\fR'th element from it (0 refers to the first element of the list).
310 In extracting the element, \fBlindex\fR observes the same rules
311 concerning braces and quotes and backslashes as the Tcl command
312 interpreter; however, variable
313 substitution and command substitution do not occur.
314 If \fIindex\fR is negative or greater than or equal to the number
315 of elements in \fIvalue\fR, then an empty
317 The interpretation of each simple \fIindex\fR value is the same as
318 for the command \fBstring index\fR, supporting simple index
319 arithmetic and indices relative to the end of the list.
321 If additional \fIindex\fR arguments are supplied, then each argument is
322 used in turn to select an element from the previous indexing operation,
323 allowing the script to select elements from sublists. The command,
326 \fBlindex\fR $a 1 2 3
332 \fBlindex\fR $a {1 2 3}
338 \fBlindex\fR [\fBlindex\fR [\fBlindex\fR $a 1] 2] 3
342 Lists can be indexed into from either end:
345 \fBlindex\fR {a b c} 0
347 \fBlindex\fR {a b c} 2
349 \fBlindex\fR {a b c} end
351 \fBlindex\fR {a b c} end-1
355 Lists or sequences of indices allow selection into lists of lists:
360 \fBlindex\fR {a b c} {}
362 \fBlindex\fR {{a b c} {d e f} {g h i}} 2 1
364 \fBlindex\fR {{a b c} {d e f} {g h i}} {2 1}
366 \fBlindex\fR {{{a b} {c d}} {{e f} {g h}}} 1 1 0
368 \fBlindex\fR {{{a b} {c d}} {{e f} {g h}}} {1 1 0}
372 List indices may also perform limited computation, adding or subtracting fixed
373 amounts from other indices:
377 \fBlindex\fR {a b c d e f} $idx+2
380 \fBlindex\fR {a b c d e f} $idx+2
384 list(n), lappend(n), linsert(n), llength(n), lsearch(n),
385 lset(n), lsort(n), lrange(n), lreplace(n),