| 1 | '\" |
| 2 | '\" Copyright (c) 1993 The Regents of the University of California. |
| 3 | '\" Copyright (c) 1994-1996 Sun Microsystems, Inc. |
| 4 | '\" Copyright (c) 2000 Scriptics Corporation. |
| 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: scan.n,v 1.9.2.1 2004/10/27 14:23:58 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 scan 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 | scan \- Parse string using conversion specifiers in the style of sscanf |
| 252 | .SH SYNOPSIS |
| 253 | \fBscan \fIstring format \fR?\fIvarName varName ...\fR? |
| 254 | .BE |
| 255 | |
| 256 | .SH INTRODUCTION |
| 257 | .PP |
| 258 | This command parses fields from an input string in the same fashion as the |
| 259 | ANSI C \fBsscanf\fR procedure and returns a count of the number of |
| 260 | conversions performed, or -1 if the end of the input string is reached |
| 261 | before any conversions have been performed. \fIString\fR gives the input |
| 262 | to be parsed and \fIformat\fR indicates how to parse it, using \fB%\fR |
| 263 | conversion specifiers as in \fBsscanf\fR. Each \fIvarName\fR gives the |
| 264 | name of a variable; when a field is scanned from \fIstring\fR the result is |
| 265 | converted back into a string and assigned to the corresponding variable. |
| 266 | If no \fIvarName\fR variables are specified, then \fBscan\fR works in an |
| 267 | inline manner, returning the data that would otherwise be stored in the |
| 268 | variables as a list. In the inline case, an empty string is returned when |
| 269 | the end of the input string is reached before any conversions have been |
| 270 | performed. |
| 271 | .SH "DETAILS ON SCANNING" |
| 272 | .PP |
| 273 | \fBScan\fR operates by scanning \fIstring\fR and \fIformat\fR together. |
| 274 | If the next character in \fIformat\fR is a blank or tab then it |
| 275 | matches any number of white space characters in \fIstring\fR (including |
| 276 | zero). |
| 277 | Otherwise, if it isn't a \fB%\fR character then it |
| 278 | must match the next character of \fIstring\fR. |
| 279 | When a \fB%\fR is encountered in \fIformat\fR, it indicates |
| 280 | the start of a conversion specifier. |
| 281 | .VS 8.4 |
| 282 | A conversion specifier contains up to four fields after the \fB%\fR: |
| 283 | a \fB*\fR, which indicates that the converted value is to be discarded |
| 284 | instead of assigned to a variable; a XPG3 position specifier; a number |
| 285 | indicating a maximum field width; a field size modifier; and a |
| 286 | conversion character. |
| 287 | .VE 8.4 |
| 288 | All of these fields are optional except for the conversion character. |
| 289 | The fields that are present must appear in the order given above. |
| 290 | .PP |
| 291 | When \fBscan\fR finds a conversion specifier in \fIformat\fR, it |
| 292 | first skips any white-space characters in \fIstring\fR (unless the |
| 293 | specifier is \fB[\fR or \fBc\fR). |
| 294 | Then it converts the next input characters according to the |
| 295 | conversion specifier and stores the result in the variable given |
| 296 | by the next argument to \fBscan\fR. |
| 297 | .PP |
| 298 | If the \fB%\fR is followed by a decimal number and a \fB$\fR, as in |
| 299 | ``\fB%2$d\fR'', then the variable to use is not taken from the next |
| 300 | sequential argument. Instead, it is taken from the argument indicated |
| 301 | by the number, where 1 corresponds to the first \fIvarName\fR. If |
| 302 | there are any positional specifiers in \fIformat\fR then all of the |
| 303 | specifiers must be positional. Every \fIvarName\fR on the argument |
| 304 | list must correspond to exactly one conversion specifier or an error |
| 305 | is generated, or in the inline case, any position can be specified |
| 306 | at most once and the empty positions will be filled in with empty strings. |
| 307 | .PP |
| 308 | The following conversion characters are supported: |
| 309 | .TP 10 |
| 310 | \fBd\fR |
| 311 | The input field must be a decimal integer. |
| 312 | It is read in and the value is stored in the variable as a decimal string. |
| 313 | .VS 8.4 |
| 314 | If the \fBl\fR or \fBL\fR field size modifier is given, the scanned |
| 315 | value will have an internal representation that is at least 64-bits in |
| 316 | size. |
| 317 | .VE 8.4 |
| 318 | .TP 10 |
| 319 | \fBo\fR |
| 320 | The input field must be an octal integer. It is read in and the |
| 321 | value is stored in the variable as a decimal string. |
| 322 | .VS 8.4 |
| 323 | If the \fBl\fR or \fBL\fR field size modifier is given, the scanned |
| 324 | value will have an internal representation that is at least 64-bits in |
| 325 | size. |
| 326 | If the value exceeds MAX_INT (017777777777 on platforms using 32-bit |
| 327 | integers when the \fBl\fR and \fBL\fR modifiers are not given), it |
| 328 | will be truncated to a signed integer. Hence, 037777777777 will |
| 329 | appear as -1 on a 32-bit machine by default. |
| 330 | .VE 8.4 |
| 331 | .TP 10 |
| 332 | \fBx\fR |
| 333 | The input field must be a hexadecimal integer. It is read in |
| 334 | and the value is stored in the variable as a decimal string. |
| 335 | .VS 8.4 |
| 336 | If the \fBl\fR or \fBL\fR field size modifier is given, the scanned |
| 337 | value will have an internal representation that is at least 64-bits in |
| 338 | size. |
| 339 | If the value exceeds MAX_INT (0x7FFFFFFF on platforms using 32-bit |
| 340 | integers when the \fBl\fR and \fBL\fR modifiers are not given), it |
| 341 | will be truncated to a signed integer. Hence, 0xFFFFFFFF will appear |
| 342 | as -1 on a 32-bit machine. |
| 343 | .VE 8.4 |
| 344 | .TP 10 |
| 345 | \fBu\fR |
| 346 | The input field must be a decimal integer. The value is stored in the |
| 347 | variable as an unsigned decimal integer string. |
| 348 | .VS 8.4 |
| 349 | If the \fBl\fR or \fBL\fR field size modifier is given, the scanned |
| 350 | value will have an internal representation that is at least 64-bits in |
| 351 | size. |
| 352 | .VE 8.4 |
| 353 | .TP 10 |
| 354 | \fBi\fR |
| 355 | The input field must be an integer. The base (i.e. decimal, octal, or |
| 356 | hexadecimal) is determined in the same fashion as described in |
| 357 | \fBexpr\fR. The value is stored in the variable as a decimal string. |
| 358 | .VS 8.4 |
| 359 | If the \fBl\fR or \fBL\fR field size modifier is given, the scanned |
| 360 | value will have an internal representation that is at least 64-bits in |
| 361 | size. |
| 362 | .VE 8.4 |
| 363 | .TP 10 |
| 364 | \fBc\fR |
| 365 | A single character is read in and its binary value is stored in |
| 366 | the variable as a decimal string. |
| 367 | Initial white space is not skipped in this case, so the input |
| 368 | field may be a white-space character. |
| 369 | This conversion is different from the ANSI standard in that the |
| 370 | input field always consists of a single character and no field |
| 371 | width may be specified. |
| 372 | .TP 10 |
| 373 | \fBs\fR |
| 374 | The input field consists of all the characters up to the next |
| 375 | white-space character; the characters are copied to the variable. |
| 376 | .TP 10 |
| 377 | \fBe\fR or \fBf\fR or \fBg\fR |
| 378 | The input field must be a floating-point number consisting |
| 379 | of an optional sign, a string of decimal digits possibly |
| 380 | containing a decimal point, and an optional exponent consisting |
| 381 | of an \fBe\fR or \fBE\fR followed by an optional sign and a string of |
| 382 | decimal digits. |
| 383 | It is read in and stored in the variable as a floating-point string. |
| 384 | .TP 10 |
| 385 | \fB[\fIchars\fB]\fR |
| 386 | The input field consists of any number of characters in |
| 387 | \fIchars\fR. |
| 388 | The matching string is stored in the variable. |
| 389 | If the first character between the brackets is a \fB]\fR then |
| 390 | it is treated as part of \fIchars\fR rather than the closing |
| 391 | bracket for the set. |
| 392 | If \fIchars\fR |
| 393 | contains a sequence of the form \fIa\fB\-\fIb\fR then any |
| 394 | character between \fIa\fR and \fIb\fR (inclusive) will match. |
| 395 | If the first or last character between the brackets is a \fB\-\fR, then |
| 396 | it is treated as part of \fIchars\fR rather than indicating a range. |
| 397 | .TP 10 |
| 398 | \fB[^\fIchars\fB]\fR |
| 399 | The input field consists of any number of characters not in |
| 400 | \fIchars\fR. |
| 401 | The matching string is stored in the variable. |
| 402 | If the character immediately following the \fB^\fR is a \fB]\fR then it is |
| 403 | treated as part of the set rather than the closing bracket for |
| 404 | the set. |
| 405 | If \fIchars\fR |
| 406 | contains a sequence of the form \fIa\fB\-\fIb\fR then any |
| 407 | character between \fIa\fR and \fIb\fR (inclusive) will be excluded |
| 408 | from the set. |
| 409 | If the first or last character between the brackets is a \fB\-\fR, then |
| 410 | it is treated as part of \fIchars\fR rather than indicating a range. |
| 411 | .TP 10 |
| 412 | \fBn\fR |
| 413 | No input is consumed from the input string. Instead, the total number |
| 414 | of characters scanned from the input string so far is stored in the variable. |
| 415 | .LP |
| 416 | The number of characters read from the input for a conversion is the |
| 417 | largest number that makes sense for that particular conversion (e.g. |
| 418 | as many decimal digits as possible for \fB%d\fR, as |
| 419 | many octal digits as possible for \fB%o\fR, and so on). |
| 420 | The input field for a given conversion terminates either when a |
| 421 | white-space character is encountered or when the maximum field |
| 422 | width has been reached, whichever comes first. |
| 423 | If a \fB*\fR is present in the conversion specifier |
| 424 | then no variable is assigned and the next scan argument is not consumed. |
| 425 | .SH "DIFFERENCES FROM ANSI SSCANF" |
| 426 | .PP |
| 427 | The behavior of the \fBscan\fR command is the same as the behavior of |
| 428 | the ANSI C \fBsscanf\fR procedure except for the following differences: |
| 429 | .IP [1] |
| 430 | \fB%p\fR conversion specifier is not currently supported. |
| 431 | .IP [2] |
| 432 | For \fB%c\fR conversions a single character value is |
| 433 | converted to a decimal string, which is then assigned to the |
| 434 | corresponding \fIvarName\fR; |
| 435 | no field width may be specified for this conversion. |
| 436 | .IP [3] |
| 437 | .VS 8.4 |
| 438 | The \fBh\fR modifier is always ignored and the \fBl\fR and \fBL\fR |
| 439 | modifiers are ignored when converting real values (i.e. type |
| 440 | \fBdouble\fR is used for the internal representation). |
| 441 | .VE 8.4 |
| 442 | .IP [4] |
| 443 | If the end of the input string is reached before any conversions have been |
| 444 | performed and no variables are given, an empty string is returned. |
| 445 | .SH EXAMPLES |
| 446 | Parse a simple color specification of the form \fI#RRGGBB\fR using |
| 447 | hexadecimal conversions with field sizes: |
| 448 | .CS |
| 449 | set string "#08D03F" |
| 450 | \fBscan\fR $string "#%2x%2x%2x" r g b |
| 451 | .CE |
| 452 | .PP |
| 453 | Parse a \fIHH:MM\fR time string, noting that this avoids problems with |
| 454 | octal numbers by forcing interpretation as decimals (if we did not |
| 455 | care, we would use the \fB%i\fR conversion instead): |
| 456 | .CS |
| 457 | set string "08:08" ;# *Not* octal! |
| 458 | if {[\fBscan\fR $string "%d:%d" hours minutes] != 2} { |
| 459 | error "not a valid time string" |
| 460 | } |
| 461 | # We have to understand numeric ranges ourselves... |
| 462 | if {$minutes < 0 || $minutes > 59} { |
| 463 | error "invalid number of minutes" |
| 464 | } |
| 465 | .CE |
| 466 | .PP |
| 467 | Break a string up into sequences of non-whitespace characters (note |
| 468 | the use of the \fB%n\fR conversion so that we get skipping over |
| 469 | leading whitespace correct): |
| 470 | .CS |
| 471 | set string " a string {with braced words} + leading space " |
| 472 | set words {} |
| 473 | while {[\fBscan\fR $string %s%n word length] == 2} { |
| 474 | lappend words $word |
| 475 | set string [string range $string $length end] |
| 476 | } |
| 477 | .CE |
| 478 | .PP |
| 479 | Parse a simple coordinate string, checking that it is complete by |
| 480 | looking for the terminating character explicitly: |
| 481 | .CS |
| 482 | set string "(5.2,-4e-2)" |
| 483 | # Note that the spaces before the literal parts of |
| 484 | # the scan pattern are significant, and that ")" is |
| 485 | # the Unicode character \\u0029 |
| 486 | if { |
| 487 | [\fBscan\fR $string " (%f ,%f %c" x y last] != 3 |
| 488 | || $last != 0x0029 |
| 489 | } then { |
| 490 | error "invalid coordinate string" |
| 491 | } |
| 492 | puts "X=$x, Y=$y" |
| 493 | .CE |
| 494 | |
| 495 | .SH "SEE ALSO" |
| 496 | format(n), sscanf(3) |
| 497 | |
| 498 | .SH KEYWORDS |
| 499 | conversion specifier, parse, scan |