| 1 | '\" |
| 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. All rights reserved. |
| 5 | '\" |
| 6 | '\" See the file "license.terms" for information on usage and redistribution |
| 7 | '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. |
| 8 | '\" |
| 9 | '\" RCS: @(#) $Id: lindex.n,v 1.7.4.1 2004/10/27 12:52:40 dkf Exp $ |
| 10 | '\" |
| 11 | '\" The definitions below are for supplemental macros used in Tcl/Tk |
| 12 | '\" manual entries. |
| 13 | '\" |
| 14 | '\" .AP type name in/out ?indent? |
| 15 | '\" Start paragraph describing an argument to a library procedure. |
| 16 | '\" type is type of argument (int, etc.), in/out is either "in", "out", |
| 17 | '\" or "in/out" to describe whether procedure reads or modifies arg, |
| 18 | '\" and indent is equivalent to second arg of .IP (shouldn't ever be |
| 19 | '\" needed; use .AS below instead) |
| 20 | '\" |
| 21 | '\" .AS ?type? ?name? |
| 22 | '\" Give maximum sizes of arguments for setting tab stops. Type and |
| 23 | '\" name are examples of largest possible arguments that will be passed |
| 24 | '\" to .AP later. If args are omitted, default tab stops are used. |
| 25 | '\" |
| 26 | '\" .BS |
| 27 | '\" Start box enclosure. From here until next .BE, everything will be |
| 28 | '\" enclosed in one large box. |
| 29 | '\" |
| 30 | '\" .BE |
| 31 | '\" End of box enclosure. |
| 32 | '\" |
| 33 | '\" .CS |
| 34 | '\" Begin code excerpt. |
| 35 | '\" |
| 36 | '\" .CE |
| 37 | '\" End code excerpt. |
| 38 | '\" |
| 39 | '\" .VS ?version? ?br? |
| 40 | '\" Begin vertical sidebar, for use in marking newly-changed parts |
| 41 | '\" of man pages. The first argument is ignored and used for recording |
| 42 | '\" the version when the .VS was added, so that the sidebars can be |
| 43 | '\" found and removed when they reach a certain age. If another argument |
| 44 | '\" is present, then a line break is forced before starting the sidebar. |
| 45 | '\" |
| 46 | '\" .VE |
| 47 | '\" End of vertical sidebar. |
| 48 | '\" |
| 49 | '\" .DS |
| 50 | '\" Begin an indented unfilled display. |
| 51 | '\" |
| 52 | '\" .DE |
| 53 | '\" End of indented unfilled display. |
| 54 | '\" |
| 55 | '\" .SO |
| 56 | '\" Start of list of standard options for a Tk widget. The |
| 57 | '\" options follow on successive lines, in four columns separated |
| 58 | '\" by tabs. |
| 59 | '\" |
| 60 | '\" .SE |
| 61 | '\" End of list of standard options for a Tk widget. |
| 62 | '\" |
| 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. |
| 68 | '\" |
| 69 | '\" .UL arg1 arg2 |
| 70 | '\" Print arg1 underlined, then print arg2 normally. |
| 71 | '\" |
| 72 | '\" RCS: @(#) $Id: man.macros,v 1.4 2000/08/25 06:18:32 ericm Exp $ |
| 73 | '\" |
| 74 | '\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages. |
| 75 | .if t .wh -1.3i ^B |
| 76 | .nr ^l \n(.l |
| 77 | .ad b |
| 78 | '\" # Start an argument description |
| 79 | .de AP |
| 80 | .ie !"\\$4"" .TP \\$4 |
| 81 | .el \{\ |
| 82 | . ie !"\\$2"" .TP \\n()Cu |
| 83 | . el .TP 15 |
| 84 | .\} |
| 85 | .ta \\n()Au \\n()Bu |
| 86 | .ie !"\\$3"" \{\ |
| 87 | \&\\$1 \\fI\\$2\\fP (\\$3) |
| 88 | .\".b |
| 89 | .\} |
| 90 | .el \{\ |
| 91 | .br |
| 92 | .ie !"\\$2"" \{\ |
| 93 | \&\\$1 \\fI\\$2\\fP |
| 94 | .\} |
| 95 | .el \{\ |
| 96 | \&\\fI\\$1\\fP |
| 97 | .\} |
| 98 | .\} |
| 99 | .. |
| 100 | '\" # define tabbing values for .AP |
| 101 | .de AS |
| 102 | .nr )A 10n |
| 103 | .if !"\\$1"" .nr )A \\w'\\$1'u+3n |
| 104 | .nr )B \\n()Au+15n |
| 105 | .\" |
| 106 | .if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n |
| 107 | .nr )C \\n()Bu+\\w'(in/out)'u+2n |
| 108 | .. |
| 109 | .AS Tcl_Interp Tcl_CreateInterp in/out |
| 110 | '\" # BS - start boxed text |
| 111 | '\" # ^y = starting y location |
| 112 | '\" # ^b = 1 |
| 113 | .de BS |
| 114 | .br |
| 115 | .mk ^y |
| 116 | .nr ^b 1u |
| 117 | .if n .nf |
| 118 | .if n .ti 0 |
| 119 | .if n \l'\\n(.lu\(ul' |
| 120 | .if n .fi |
| 121 | .. |
| 122 | '\" # BE - end boxed text (draw box now) |
| 123 | .de BE |
| 124 | .nf |
| 125 | .ti 0 |
| 126 | .mk ^t |
| 127 | .ie n \l'\\n(^lu\(ul' |
| 128 | .el \{\ |
| 129 | .\" Draw four-sided box normally, but don't draw top of |
| 130 | .\" box if the box started on an earlier page. |
| 131 | .ie !\\n(^b-1 \{\ |
| 132 | \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' |
| 133 | .\} |
| 134 | .el \}\ |
| 135 | \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' |
| 136 | .\} |
| 137 | .\} |
| 138 | .fi |
| 139 | .br |
| 140 | .nr ^b 0 |
| 141 | .. |
| 142 | '\" # VS - start vertical sidebar |
| 143 | '\" # ^Y = starting y location |
| 144 | '\" # ^v = 1 (for troff; for nroff this doesn't matter) |
| 145 | .de VS |
| 146 | .if !"\\$2"" .br |
| 147 | .mk ^Y |
| 148 | .ie n 'mc \s12\(br\s0 |
| 149 | .el .nr ^v 1u |
| 150 | .. |
| 151 | '\" # VE - end of vertical sidebar |
| 152 | .de VE |
| 153 | .ie n 'mc |
| 154 | .el \{\ |
| 155 | .ev 2 |
| 156 | .nf |
| 157 | .ti 0 |
| 158 | .mk ^t |
| 159 | \h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n' |
| 160 | .sp -1 |
| 161 | .fi |
| 162 | .ev |
| 163 | .\} |
| 164 | .nr ^v 0 |
| 165 | .. |
| 166 | '\" # Special macro to handle page bottom: finish off current |
| 167 | '\" # box/sidebar if in box/sidebar mode, then invoked standard |
| 168 | '\" # page bottom macro. |
| 169 | .de ^B |
| 170 | .ev 2 |
| 171 | 'ti 0 |
| 172 | 'nf |
| 173 | .mk ^t |
| 174 | .if \\n(^b \{\ |
| 175 | .\" Draw three-sided box if this is the box's first page, |
| 176 | .\" draw two sides but no top otherwise. |
| 177 | .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 |
| 178 | .el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c |
| 179 | .\} |
| 180 | .if \\n(^v \{\ |
| 181 | .nr ^x \\n(^tu+1v-\\n(^Yu |
| 182 | \kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c |
| 183 | .\} |
| 184 | .bp |
| 185 | 'fi |
| 186 | .ev |
| 187 | .if \\n(^b \{\ |
| 188 | .mk ^y |
| 189 | .nr ^b 2 |
| 190 | .\} |
| 191 | .if \\n(^v \{\ |
| 192 | .mk ^Y |
| 193 | .\} |
| 194 | .. |
| 195 | '\" # DS - begin display |
| 196 | .de DS |
| 197 | .RS |
| 198 | .nf |
| 199 | .sp |
| 200 | .. |
| 201 | '\" # DE - end display |
| 202 | .de DE |
| 203 | .fi |
| 204 | .RE |
| 205 | .sp |
| 206 | .. |
| 207 | '\" # SO - start of list of standard options |
| 208 | .de SO |
| 209 | .SH "STANDARD OPTIONS" |
| 210 | .LP |
| 211 | .nf |
| 212 | .ta 5.5c 11c |
| 213 | .ft B |
| 214 | .. |
| 215 | '\" # SE - end of list of standard options |
| 216 | .de SE |
| 217 | .fi |
| 218 | .ft R |
| 219 | .LP |
| 220 | See the \\fBoptions\\fR manual entry for details on the standard options. |
| 221 | .. |
| 222 | '\" # OP - start of full description for a single option |
| 223 | .de OP |
| 224 | .LP |
| 225 | .nf |
| 226 | .ta 4c |
| 227 | Command-Line Name: \\fB\\$1\\fR |
| 228 | Database Name: \\fB\\$2\\fR |
| 229 | Database Class: \\fB\\$3\\fR |
| 230 | .fi |
| 231 | .IP |
| 232 | .. |
| 233 | '\" # CS - begin code excerpt |
| 234 | .de CS |
| 235 | .RS |
| 236 | .nf |
| 237 | .ta .25i .5i .75i 1i |
| 238 | .. |
| 239 | '\" # CE - end code excerpt |
| 240 | .de CE |
| 241 | .fi |
| 242 | .RE |
| 243 | .. |
| 244 | .de UL |
| 245 | \\$1\l'|0\(ul'\\$2 |
| 246 | .. |
| 247 | .TH lindex n 8.4 Tcl "Tcl Built-In Commands" |
| 248 | .BS |
| 249 | '\" Note: do not modify the .SH NAME line immediately below! |
| 250 | .SH NAME |
| 251 | lindex \- Retrieve an element from a list |
| 252 | .SH SYNOPSIS |
| 253 | \fBlindex \fIlist ?index...?\fR |
| 254 | .BE |
| 255 | .SH DESCRIPTION |
| 256 | .PP |
| 257 | .VS 8.4 |
| 258 | The \fBlindex\fP command accepts a parameter, \fIlist\fP, which |
| 259 | it treats as a Tcl list. It also accepts zero or more \fIindices\fP into |
| 260 | the list. The indices may be presented either consecutively on the |
| 261 | command line, or grouped in a |
| 262 | Tcl list and presented as a single argument. |
| 263 | .PP |
| 264 | If no indices are presented, the command takes the form: |
| 265 | .CS |
| 266 | lindex list |
| 267 | .CE |
| 268 | or |
| 269 | .CS |
| 270 | lindex list {} |
| 271 | .CE |
| 272 | In this case, the return value of \fBlindex\fR is simply the value of the |
| 273 | \fIlist\fR parameter. |
| 274 | .PP |
| 275 | When presented with a single index, the \fBlindex\fR command |
| 276 | treats \fIlist\fR as a Tcl list and returns the |
| 277 | .VE |
| 278 | \fIindex\fR'th element from it (0 refers to the first element of the list). |
| 279 | In extracting the element, \fBlindex\fR observes the same rules |
| 280 | concerning braces and quotes and backslashes as the Tcl command |
| 281 | interpreter; however, variable |
| 282 | substitution and command substitution do not occur. |
| 283 | If \fIindex\fR is negative or greater than or equal to the number |
| 284 | of elements in \fIvalue\fR, then an empty |
| 285 | string is returned. |
| 286 | If \fIindex\fR has the value \fBend\fR, it refers to the last element |
| 287 | in the list, and \fBend\-\fIinteger\fR refers to the last element in |
| 288 | the list minus the specified integer offset. |
| 289 | .PP |
| 290 | .VS 8.4 |
| 291 | If additional \fIindex\fR arguments are supplied, then each argument is |
| 292 | used in turn to select an element from the previous indexing operation, |
| 293 | allowing the script to select elements from sublists. The command, |
| 294 | .CS |
| 295 | lindex $a 1 2 3 |
| 296 | .CE |
| 297 | or |
| 298 | .CS |
| 299 | lindex $a {1 2 3} |
| 300 | .CE |
| 301 | is synonymous with |
| 302 | .CS |
| 303 | lindex [lindex [lindex $a 1] 2] 3 |
| 304 | .CE |
| 305 | .SH EXAMPLES |
| 306 | .CS |
| 307 | \fBlindex\fR {a b c} \fI=> a b c\fR |
| 308 | \fBlindex\fR {a b c} {} \fI=> a b c\fR |
| 309 | \fBlindex\fR {a b c} 0 \fI=> a\fR |
| 310 | \fBlindex\fR {a b c} 2 \fI=> c\fR |
| 311 | \fBlindex\fR {a b c} end \fI=> c\fR |
| 312 | \fBlindex\fR {a b c} end-1 \fI=> b\fR |
| 313 | \fBlindex\fR {{a b c} {d e f} {g h i}} 2 1 \fI=> h\fR |
| 314 | \fBlindex\fR {{a b c} {d e f} {g h i}} {2 1} \fI=> h\fR |
| 315 | \fBlindex\fR {{{a b} {c d}} {{e f} {g h}}} 1 1 0 \fI=> g\fR |
| 316 | \fBlindex\fR {{{a b} {c d}} {{e f} {g h}}} {1 1 0} \fI=> g\fR |
| 317 | .CE |
| 318 | .VE |
| 319 | .SH "SEE ALSO" |
| 320 | list(n), lappend(n), linsert(n), llength(n), lsearch(n), |
| 321 | .VS 8.4 |
| 322 | lset(n), |
| 323 | .VE |
| 324 | lsort(n), |
| 325 | lrange(n), lreplace(n) |
| 326 | |
| 327 | .SH KEYWORDS |
| 328 | element, index, list |