1 '\" te 2 .\" Copyright 2014 Garrett D'Amore <garrett@damore.org> 3 .\" Copyright (c) 2008, Sun Microsystems, Inc. All Rights Reserved. 4 .\" Copyright 1989 AT&T 5 .\" Portions Copyright (c) 1994 Man-cgi 1.15, Panagiotis Christias (christia@softlab.ntua.gr) 6 .\" Portions Copyright (c) 1996-2008 Modified for NetBSD by Kimmo Suominen (kimmo@suominen.com) 7 .\" Portions Copyright (c) 1992, X/Open Company Limited. All Rights Reserved. 8 .\" Sun Microsystems, Inc. gratefully acknowledges The Open Group for permission to reproduce portions of its copyrighted documentation. Original documentation from The Open Group can be obtained online at 9 .\" http://www.opengroup.org/bookstore/. 10 .\" The Institute of Electrical and Electronics Engineers and The Open Group, have given us permission to reprint portions of their documentation. In the following statement, the phrase "this text" refers to portions of the system documentation. Portions of this text are reprinted and reproduced in electronic form in the Sun OS Reference Manual, from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between these versions and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html. 11 .\" This notice shall appear on any product containing this material. 12 .\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License. 13 .\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License. 14 .\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner] 15 .TH STRING 3C "Jun 21, 2013" 16 .SH NAME 17 string, strcasecmp, strcasecmp_l, strncasecmp, strncasecmp_l, strcat, strncat, 18 strlcat, strchr, strrchr, 19 strcmp, strncmp, strcpy, strncpy, strlcpy, strcspn, strspn, strdup, strlen, 20 strnlen, strpbrk, strsep, strstr, strtok, strtok_r \- string operations 21 .SH SYNOPSIS 22 .LP 23 .nf 24 #include <strings.h> 25 26 \fBint\fR \fBstrcasecmp\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR); 27 .fi 28 .LP 29 .nf 30 \fBint\fR \fBstrcasecmp_l\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR, \fBlocale_t\fR \fIloc\fR); 31 .fi 32 .LP 33 .nf 34 \fBint\fR \fBstrncasecmp\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR, \fBsize_t\fR \fIn\fR); 35 .fi 36 .LP 37 .nf 38 \fBint\fR \fBstrncasecmp_l\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR, \fBsize_t\fR \fIn\fR, \fBlocale_t\fR \fIloc\fR); 39 .fi 40 .LP 41 .nf 42 #include <string.h> 43 44 \fBchar *\fR\fBstrcat\fR(\fBchar *restrict\fR \fIs1\fR, \fBconst char *restrict\fR \fIs2\fR); 45 .fi 46 .LP 47 .nf 48 \fBchar *\fR\fBstrncat\fR(\fBchar *restrict\fR \fIs1\fR, \fBconst char *restrict\fR \fIs2\fR, \fBsize_t\fR \fIn\fR); 49 .fi 50 .LP 51 .nf 52 \fBsize_t\fR \fBstrlcat\fR(\fBchar *\fR\fIdst\fR, \fBconst char *\fR\fIsrc\fR, \fBsize_t\fR \fIdstsize\fR); 53 .fi 54 .LP 55 .nf 56 \fBchar *\fR\fBstrchr\fR(\fBconst char *\fR\fIs\fR, \fBint\fR \fIc\fR); 57 .fi 58 .LP 59 .nf 60 \fBchar *\fR\fBstrrchr\fR(\fBconst char *\fR\fIs\fR, \fBint\fR \fIc\fR); 61 .fi 62 .LP 63 .nf 64 \fBint\fR \fBstrcmp\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR); 65 .fi 66 .LP 67 .nf 68 \fBint\fR \fBstrncmp\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR, \fBsize_t\fR \fIn\fR); 69 .fi 70 .LP 71 .nf 72 \fBchar *\fR\fBstrcpy\fR(\fBchar *restrict\fR \fIs1\fR, \fBconst char *restrict\fR \fIs2\fR); 73 .fi 74 .LP 75 .nf 76 \fBchar *\fR\fBstrncpy\fR(\fBchar *restrict\fR \fIs1\fR, \fBconst char *restrict\fR \fIs2\fR, \fBsize_t\fR \fIn\fR); 77 .fi 78 .LP 79 .nf 80 \fBsize_t\fR \fBstrlcpy\fR(\fBchar *\fR\fIdst\fR, \fBconst char *\fR\fIsrc\fR, \fBsize_t\fR \fIdstsize\fR); 81 .fi 82 .LP 83 .nf 84 \fBsize_t\fR \fBstrcspn\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR); 85 .fi 86 .LP 87 .nf 88 \fBsize_t\fR \fBstrspn\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR); 89 .fi 90 .LP 91 .nf 92 \fBchar *\fR\fBstrdup\fR(\fBconst char *\fR\fIs1\fR); 93 .fi 94 .LP 95 .nf 96 \fBsize_t\fR \fBstrlen\fR(\fBconst char *\fR\fIs\fR); 97 .fi 98 .LP 99 .nf 100 \fBsize_t\fR \fBstrnlen\fR(\fBconst char *\fR\fIs\fR, \fBsize_t\fR \fIn\fR); 101 .fi 102 .LP 103 .nf 104 \fBchar *\fR\fBstrpbrk\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR); 105 .fi 106 .LP 107 .nf 108 \fBchar *\fR\fBstrsep\fR(\fBchar **\fR\fIstringp\fR, \fBconst char *\fR\fIdelim\fR); 109 .fi 110 .LP 111 .nf 112 \fBchar *\fR\fBstrstr\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR); 113 .fi 114 .LP 115 .nf 116 \fBchar *\fR\fBstrtok\fR(\fBchar *restrict\fR \fIs1\fR, \fBconst char *restrict\fR \fIs2\fR); 117 .fi 118 .LP 119 .nf 120 \fBchar *\fR\fBstrtok_r\fR(\fBchar *restrict\fR \fIs1\fR, \fBconst char *restrict\fR \fIs2\fR, 121 \fBchar **restrict\fR \fIlasts\fR); 122 .fi 123 .SS "ISO C++" 124 .LP 125 .nf 126 #include <string.h> 127 128 \fBconst char *\fR\fBstrchr\fR(\fBconst char *\fR\fIs\fR, \fBint\fR \fIc\fR); 129 .fi 130 .LP 131 .nf 132 \fBconst char *\fR\fBstrpbrk\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR); 133 .fi 134 .LP 135 .nf 136 \fBconst char *\fR\fBstrrchr\fR(\fBconst char *\fR\fIs\fR, \fBint\fR \fIc\fR); 137 .fi 138 .LP 139 .nf 140 \fBconst char *\fR\fBstrstr\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR); 141 .fi 142 .LP 143 .nf 144 #include <cstring> 145 146 \fBchar *std::\fR\fBstrchr\fR(\fBchar *\fR\fIs\fR, \fBint\fR \fIc\fR); 147 .fi 148 .LP 149 .nf 150 \fBchar *std::\fR\fBstrpbrk\fR(\fBchar *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR); 151 .fi 152 .LP 153 .nf 154 \fBchar *std::\fR\fBstrrchr\fR(\fBchar *\fR\fIs\fR, \fBint\fR \fIc\fR); 155 .fi 156 .LP 157 .nf 158 \fBchar *std::\fR\fBstrstr\fR(\fBchar *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR); 159 .fi 160 .SH DESCRIPTION 161 .LP 162 The arguments \fIs\fR, \fIs1\fR, and \fIs2\fR point to strings (arrays of 163 characters terminated by a null character). The \fBstrcat()\fR, 164 \fBstrncat()\fR, \fBstrlcat()\fR, \fBstrcpy()\fR, \fBstrncpy()\fR, 165 \fBstrlcpy()\fR, \fBstrsep()\fR, \fBstrtok()\fR, and \fBstrtok_r()\fR functions 166 all alter their first argument. Additionally, the \fBstrcat()\fR and 167 \fBstrcpy()\fR functions do not check for overflow of the array. 168 .SS "\fBstrcasecmp()\fR, \fBstrncasecmp()\fR" 169 .sp 170 .LP 171 The \fBstrcasecmp()\fR and \fBstrncasecmp()\fR functions are case-insensitive 172 versions of \fBstrcmp()\fR and \fBstrncmp()\fR respectively, described below. 173 .LP 174 The \fBstrcasecmp()\fR and \fBstrncasecmp()\fR functions compare two strings 175 byte-by-byte, after 176 converting each upper-case character to lower-case (as determined by the 177 \fBLC_CTYPE\fR category of the current locale). Note that neither the contents 178 pointed to by \fIs1\fR nor \fIs2\fR are modified. 179 .LP 180 The functions return an integer 181 greater than, equal to, or less than 0, if the string pointed to by \fIs1\fR 182 is greater than, equal to, or less than the string pointed to by \fIs2\fR 183 respectively. The sign of a non-zero return value is determined by the sign of 184 the difference between the values of the first pair of bytes that differ in the 185 .LP 186 The \fBstrncasecmp()\fR function examines at most \fIn\fR bytes from each 187 string. 188 .SS "\fBstrcasecmp_l()\fR, \fBstrncasecmp_l()\fR" 189 .LP 190 The \fBstrcasecmp_l()\fR and \fBstrncasecmp_l()\fR functions behave identically 191 to \fBstrcasecmp()\fR and \fBstrncasecmp()\fR, except instead of operating in 192 the current locale, they instead operate in the locale specified by \fIloc\fR. 193 .SS "\fBstrcat()\fR, \fBstrncat()\fR, \fBstrlcat()\fR" 194 .LP 195 The \fBstrcat()\fR function appends a copy of string \fIs2\fR, including the 196 terminating null character, to the end of string \fIs1\fR. The \fBstrncat()\fR 197 function appends at most \fIn\fR characters. Each returns a pointer to the 198 null-terminated result. The initial character of \fIs2\fR overrides the null 199 character at the end of \fIs1\fR. If copying takes place between objects that 200 overlap, the behavior of \fBstrcat()\fR, \fBstrncat()\fR, and \fBstrlcat()\fR 201 is undefined. 202 .LP 203 The \fBstrlcat()\fR function appends at most 204 (\fIdstsize\fR-\fBstrlen\fR(\fIdst\fR)-1) characters of \fIsrc\fR to \fIdst\fR 205 (\fIdstsize\fR being the size of the string buffer \fIdst\fR). If the string 206 pointed to by \fIdst\fR contains a null-terminated string that fits into 207 \fIdstsize\fR bytes when \fBstrlcat()\fR is called, the string pointed to by 208 \fIdst\fR will be a null-terminated string that fits in \fIdstsize\fR bytes 209 (including the terminating null character) when it completes, and the initial 210 character of \fIsrc\fR will override the null character at the end of 211 \fIdst\fR. If the string pointed to by \fIdst\fR is longer than \fIdstsize\fR 212 bytes when \fBstrlcat()\fR is called, the string pointed to by \fIdst\fR will 213 not be changed. The function returns 214 \fBmin\fR{\fIdstsize\fR,\fBstrlen\fR(\fIdst\fR)}+\fBstrlen\fR(\fIsrc\fR). 215 Buffer overflow can be checked as follows: 216 .sp 217 .in +2 218 .nf 219 if (strlcat(dst, src, dstsize) >= dstsize) 220 return \(mi1; 221 .fi 222 .in -2 223 .SS "\fBstrchr()\fR, \fBstrrchr()\fR" 224 .LP 225 The \fBstrchr()\fR function returns a pointer to the first occurrence of 226 \fIc\fR (converted to a \fBchar\fR) in string \fIs\fR, or a null pointer if 227 \fIc\fR does not occur in the string. The \fBstrrchr()\fR function returns a 228 pointer to the last occurrence of \fIc\fR. The null character terminating a 229 string is considered to be part of the string. 230 .SS "\fBstrcmp()\fR, \fBstrncmp()\fR" 231 .LP 232 The \fBstrcmp()\fR function compares two strings byte-by-byte, according to the 233 ordering of your machine's character set. The function returns an integer 234 greater than, equal to, or less than 0, if the string pointed to by \fIs1\fR 235 is greater than, equal to, or less than the string pointed to by \fIs2\fR 236 respectively. The sign of a non-zero return value is determined by the sign of 237 the difference between the values of the first pair of bytes that differ in the 238 strings being compared. The \fBstrncmp()\fR function makes the same comparison 239 but looks at a maximum of \fIn\fR bytes. Bytes following a null byte are not 240 compared. 241 .SS "\fBstrcpy()\fR, \fBstrncpy()\fR, \fBstrlcpy()\fR" 242 .LP 243 The \fBstrcpy()\fR function copies string \fIs2\fR to \fIs1\fR, including the 244 terminating null character, stopping after the null character has been copied. 245 The \fBstrncpy()\fR function copies exactly \fIn\fR bytes, truncating \fIs2\fR 246 or adding null characters to \fIs1\fR if necessary. The result will not be 247 null-terminated if the length of \fIs2\fR is \fIn\fR or more. Each function 248 returns \fIs1\fR. If copying takes place between objects that overlap, the 249 behavior of \fBstrcpy()\fR, \fBstrncpy()\fR, and \fBstrlcpy()\fR is undefined. 250 .LP 251 The \fBstrlcpy()\fR function copies at most \fIdstsize\fR\(mi1 characters 252 (\fIdstsize\fR being the size of the string buffer \fIdst\fR) from \fIsrc\fR 253 to \fIdst\fR, truncating \fIsrc\fR if necessary. The result is always 254 null-terminated. The function returns \fBstrlen\fR(\fIsrc\fR). Buffer overflow 255 can be checked as follows: 256 .sp 257 .in +2 258 .nf 259 if (strlcpy(dst, src, dstsize) >= dstsize) 260 return \(mi1; 261 .fi 262 .in -2 263 264 .SS "\fBstrcspn()\fR, \fBstrspn()\fR" 265 .LP 266 The \fBstrcspn()\fR function returns the length of the initial segment of 267 string \fIs1\fR that consists entirely of characters not from string \fIs2\fR. 268 The \fBstrspn()\fR function returns the length of the initial segment of string 269 \fIs1\fR that consists entirely of characters from string \fIs2\fR. 270 .SS "\fBstrdup()\fR" 271 .LP 272 The \fBstrdup()\fR function returns a pointer to a new string that is a 273 duplicate of the string pointed to by \fIs1\fR. The returned pointer can be 274 passed to \fBfree()\fR. The space for the new string is obtained using 275 \fBmalloc\fR(3C). If the new string cannot be created, a null pointer is 276 returned and \fBerrno\fR may be set to \fBENOMEM\fR to indicate that the 277 storage space available is insufficient. 278 .SS "\fBstrlen()\fR, \fBstrnlen()\fR" 279 .sp 280 The \fBstrlen()\fR function returns the number of bytes in \fIs\fR, not 281 including the terminating null character. 282 .LP 283 The \fBstrnlen()\fR function returns the smaller of \fIn\fR or the number of 284 bytes in \fIs\fR, not including the terminating null character. The 285 \fBstrnlen()\fR function never examines more than \fIn\fR bytes of the string 286 pointed to by \fIs\fR. 287 .SS "\fBstrpbrk()\fR" 288 .LP 289 The \fBstrpbrk()\fR function returns a pointer to the first occurrence in 290 string \fIs1\fR of any character from string \fIs2\fR, or a null pointer if no 291 character from \fIs2\fR exists in \fIs1\fR. 292 .SS "\fBstrsep()\fR" 293 .LP 294 The \fBstrsep()\fR function locates, in the null-terminated string referenced 295 by *\fIstringp\fR, the first occurrence of any character in the string 296 \fIdelim\fR (or the terminating `\e0' character) and replaces it with a `\e0'. 297 The location of the next character after the delimiter character (or 298 \fINULL\fR, if the end of the string was reached) is stored in *\fIstringp\fR. 299 The original value of *\fIstringp\fR is returned. 300 .LP 301 An ``empty'' field (one caused by two adjacent delimiter characters) can be 302 detected by comparing the location referenced by the pointer returned by 303 \fBstrsep()\fR to `\e0'. 304 .LP 305 If *\fIstringp\fR is initially \fINULL\fR, \fBstrsep()\fR returns \fINULL\fR. 306 .SS "\fBstrstr()\fR" 307 .LP 308 The \fBstrstr()\fR function locates the first occurrence of the string \fIs2\fR 309 (excluding the terminating null character) in string \fIs1\fR and returns a 310 pointer to the located string, or a null pointer if the string is not found. If 311 \fIs2\fR points to a string with zero length (that is, the string \fB""\fR), 312 the function returns \fIs1\fR. 313 .SS "\fBstrtok()\fR" 314 .LP 315 A sequence of calls to \fBstrtok()\fR breaks the string pointed to by \fIs1\fR 316 into a sequence of tokens, each of which is delimited by a byte from the string 317 pointed to by \fIs2\fR. The first call in the sequence has \fIs1\fR as its 318 first argument, and is followed by calls with a null pointer as their first 319 argument. The separator string pointed to by \fIs2\fR can be different from 320 call to call. 321 .LP 322 The first call in the sequence searches the string pointed to by \fIs1\fR for 323 the first byte that is not contained in the current separator string pointed to 324 by \fIs2\fR. If no such byte is found, then there are no tokens in the string 325 pointed to by \fIs1\fR and \fBstrtok()\fR returns a null pointer. If such a 326 byte is found, it is the start of the first token. 327 .LP 328 The \fBstrtok()\fR function then searches from there for a byte that is 329 contained in the current separator string. If no such byte is found, the 330 current token extends to the end of the string pointed to by \fIs1\fR, and 331 subsequent searches for a token return a null pointer. If such a byte is found, 332 it is overwritten by a null byte that terminates the current token. The 333 \fBstrtok()\fR function saves a pointer to the following byte in 334 thread-specific data, from which the next search for a token starts. 335 .LP 336 Each subsequent call, with a null pointer as the value of the first argument, 337 starts searching from the saved pointer and behaves as described above. 338 .LP 339 See Example 1, 2, and 3 in the \fBEXAMPLES\fR section for examples of 340 \fBstrtok()\fR usage and the explanation in \fBNOTES\fR. 341 .SS "\fBstrtok_r()\fR" 342 .LP 343 The \fBstrtok_r()\fR function considers the null-terminated string \fIs1\fR as 344 a sequence of zero or more text tokens separated by spans of one or more 345 characters from the separator string \fIs2\fR. The argument \fIlasts\fR points 346 to a user-provided pointer which points to stored information necessary for 347 \fBstrtok_r()\fR to continue scanning the same string. 348 .LP 349 In the first call to \fBstrtok_r()\fR, \fIs1\fR points to a null-terminated 350 string, \fIs2\fR to a null-terminated string of separator characters, and the 351 value pointed to by \fIlasts\fR is ignored. The \fBstrtok_r()\fR function 352 returns a pointer to the first character of the first token, writes a null 353 character into \fIs1\fR immediately following the returned token, and updates 354 the pointer to which \fIlasts\fR points. 355 .LP 356 In subsequent calls, \fIs1\fR is a null pointer and \fIlasts\fR is unchanged 357 from the previous call so that subsequent calls move through the string 358 \fIs1\fR, returning successive tokens until no tokens remain. The separator 359 string \fIs2\fR can be different from call to call. When no token remains in 360 \fIs1\fR, a null pointer is returned. 361 .LP 362 See Example 3 in the \fBEXAMPLES\fR section for an example of \fBstrtok_r()\fR 363 usage and the explanation in \fBNOTES\fR. 364 .SH EXAMPLES 365 .LP 366 \fBExample 1 \fRSearch for word separators. 367 .LP 368 The following example searches for tokens separated by space characters. 369 370 .sp 371 .in +2 372 .nf 373 #include <string.h> 374 \&... 375 char *token; 376 char line[] = "LINE TO BE SEPARATED"; 377 char *search = " "; 378 379 /* Token will point to "LINE". */ 380 token = strtok(line, search); 381 382 /* Token will point to "TO". */ 383 token = strtok(NULL, search); 384 .fi 385 .in -2 386 387 .LP 388 \fBExample 2 \fRBreak a Line. 389 .LP 390 The following example uses strtok to break a line into two character strings 391 separated by any combination of SPACEs, TABs, or NEWLINEs. 392 393 .sp 394 .in +2 395 .nf 396 #include <string.h> 397 \&... 398 struct element { 399 char *key; 400 char *data; 401 }; 402 \&... 403 char line[LINE_MAX]; 404 char *key, *data; 405 \&... 406 key = strtok(line, " \en"); 407 data = strtok(NULL, " \en"); 408 .fi 409 .in -2 410 411 .LP 412 \fBExample 3 \fRSearch for tokens. 413 .LP 414 The following example uses both \fBstrtok()\fR and \fBstrtok_r()\fR to search 415 for tokens separated by one or more characters from the string pointed to by 416 the second argument, "/". 417 418 .sp 419 .in +2 420 .nf 421 #define __EXTENSIONS__ 422 #include <stdio.h> 423 #include <string.h> 424 425 int 426 main() { 427 char *buf="5/90/45"; 428 char *token; 429 char *lasts; 430 431 printf("tokenizing \e"%s\e" with strtok():\en", buf); 432 if ((token = strtok(buf, "/")) != NULL) { 433 printf("token = "%s\e"\en", token); 434 while ((token = strtok(NULL, "/")) != NULL) { 435 printf("token = \e"%s\e"\en", token); 436 } 437 } 438 439 buf = "//5//90//45//"; 440 printf("\entokenizing \e"%s\e" with strtok_r():\en", buf); 441 if ((token = strtok_r(buf, "/", &lasts)) != NULL) { 442 printf("token = \e"%s\e"\en", token); 443 while ((token = strtok_r(NULL, "/", &lasts)) != NULL) { 444 printf("token = \e"%s\e"\en", token); 445 } 446 } 447 } 448 .fi 449 .in -2 450 451 .LP 452 When compiled and run, this example produces the following output: 453 454 .sp 455 .in +2 456 .nf 457 tokenizing "5/90/45" with \fBstrtok()\fR: 458 token = "5" 459 token = "90" 460 token = "45" 461 462 tokenizing "//5//90//45//" with \fBstrtok_r()\fR: 463 token = "5" 464 token = "90" 465 token = "45" 466 .fi 467 .in -2 468 469 .SH ATTRIBUTES 470 .LP 471 See \fBattributes\fR(5) for descriptions of the following attributes: 472 .TS 473 box; 474 c | c 475 l | l . 476 ATTRIBUTE TYPE ATTRIBUTE VALUE 477 _ 478 Interface Stability See below. 479 _ 480 MT-Level See below. 481 _ 482 Standard See below. 483 .TE 484 485 .LP 486 The 487 \fBstrlcat()\fR, \fBstrlcpy()\fR, and \fBstrsep()\fR functions are Committed. 488 All the rest are Standard. 489 .LP 490 The \fBstrtok()\fR and \fBstrdup()\fR functions are MT-Safe. The remaining 491 functions are Async-Signal-Safe. 492 .LP 493 For all except \fBstrlcat()\fR, \fBstrlcpy()\fR, and \fBstrsep()\fR, see 494 \fBstandards\fR(5). 495 .SH SEE ALSO 496 .LP 497 \fBmalloc\fR(3C), 498 \fBnewlocale(3C), \fBsetlocale\fR(3C), \fBstrxfrm\fR(3C), \fBuselocale\fR(3C), 499 \fBattributes\fR(5), \fBstandards\fR(5) 500 .SH NOTES 501 .LP 502 When compiling multithreaded applications, the \fB_REENTRANT\fR flag must be 503 defined on the compile line. This flag should only be used in multithreaded 504 applications. 505 .LP 506 A single-threaded application can gain access to \fBstrtok_r()\fR only by 507 defining \fB__EXTENSIONS__\fR or by defining \fB_POSIX_C_SOURCE\fR to a value 508 greater than or equal to 199506L. 509 .LP 510 Except where noted otherwise, all of these functions assume the default 511 locale ``C.'' For some locales, 512 \fBstrxfrm\fR(3C) should be applied to the strings before they are passed to 513 the functions. 514 .LP 515 The \fBstrtok()\fR function is safe to use in multithreaded applications 516 because it saves its internal state in a thread-specific data area. However, 517 its use is discouraged, even for single-threaded applications. The 518 \fBstrtok_r()\fR function should be used instead. 519 .LP 520 Do not pass the address of a character string literal as the argument \fIs1\fR 521 to either \fBstrtok()\fR or \fBstrtok_r()\fR. Similarly, do not pass a pointer 522 to the address of a character string literal as the argument \fIstringp\fR to 523 \fBstrsep()\fR. These functions can modify the storage pointed to by \fIs1\fR 524 in the case of \fBstrtok()\fR and \fBstrtok_r()\fR or *\fIstringp\fR in the 525 case of \fBstrsep()\fR. The C99 standard specifies that attempting to modify 526 the storage occupied by a string literal results in undefined behavior. This 527 allows compilers (including \fBgcc\fR and the Sun Studio compilers when the 528 \fB-xstrconst\fR flag is used) to place string literals in read-only memory. 529 Note that in Example 1 above, this problem is avoided because the variable 530 \fIline\fR is declared as a writable array of type \fBchar\fR that is 531 initialized by a string literal rather than a pointer to \fBchar\fR that points 532 to a string literal.