lib/string.in.h

   1 /* A GNU-like <string.h>.
   2
   3    Copyright (C) 1995-1996, 2001-2007 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software Foundation,
  17    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  18
  19 #ifndef _GL_STRING_H
  20
  21 /* The include_next requires a split double-inclusion guard.  */
  22 #@INCLUDE_NEXT@ @NEXT_STRING_H@
  23
  24 #ifndef _GL_STRING_H
  25 #define _GL_STRING_H
  26
  27
  28 /* The definition of GL_LINK_WARNING is copied here.  */
  29
  30
  31 /* GCC 2.95 and later have "__restrict"; C99 compilers have
  32    "restrict", and "configure" may have defined "restrict".
  33    Other compilers use __restrict, __restrict__, and _Restrict, and
  34    'configure' might #define 'restrict' to those words.  */
  35 #ifndef __restrict
  36 # if ! (2 < __GNUC__ || (2 == __GNUC__ && 95 <= __GNUC_MINOR__))
  37 #  if 199901L <= __STDC_VERSION__
  38 #   define __restrict restrict
  39 #  else
  40 #   define __restrict
  41 #  endif
  42 # endif
  43 #endif
  44
  45 #ifdef __cplusplus
  46 extern "C" {
  47 #endif
  48
  49 /* Return the first occurrence of NEEDLE in HAYSTACK.  */
  50 #if @GNULIB_MEMMEM@
  51 # if ! @HAVE_DECL_MEMMEM@
  52 extern void *memmem (void const *__haystack, size_t __haystack_len,
  53                      void const *__needle, size_t __needle_len);
  54 # endif
  55 #elif defined GNULIB_POSIXCHECK
  56 # undef memmem
  57 # define memmem(a,al,b,bl) \
  58     (GL_LINK_WARNING ("memmem is unportable - " \
  59                       "use gnulib module memmem for portability"), \
  60      memmem (a, al, b, bl))
  61 #endif
  62
  63 /* Copy N bytes of SRC to DEST, return pointer to bytes after the
  64    last written byte.  */
  65 #if @GNULIB_MEMPCPY@
  66 # if ! @HAVE_MEMPCPY@
  67 extern void *mempcpy (void *__restrict __dest, void const *__restrict __src,
  68                       size_t __n);
  69 # endif
  70 #elif defined GNULIB_POSIXCHECK
  71 # undef mempcpy
  72 # define mempcpy(a,b,n) \
  73     (GL_LINK_WARNING ("mempcpy is unportable - " \
  74                       "use gnulib module mempcpy for portability"), \
  75      mempcpy (a, b, n))
  76 #endif
  77
  78 /* Search backwards through a block for a byte (specified as an int).  */
  79 #if @GNULIB_MEMRCHR@
  80 # if ! @HAVE_DECL_MEMRCHR@
  81 extern void *memrchr (void const *, int, size_t);
  82 # endif
  83 #elif defined GNULIB_POSIXCHECK
  84 # undef memrchr
  85 # define memrchr(a,b,c) \
  86     (GL_LINK_WARNING ("memrchr is unportable - " \
  87                       "use gnulib module memrchr for portability"), \
  88      memrchr (a, b, c))
  89 #endif
  90
  91 /* Copy SRC to DST, returning the address of the terminating '\0' in DST.  */
  92 #if @GNULIB_STPCPY@
  93 # if ! @HAVE_STPCPY@
  94 extern char *stpcpy (char *__restrict __dst, char const *__restrict __src);
  95 # endif
  96 #elif defined GNULIB_POSIXCHECK
  97 # undef stpcpy
  98 # define stpcpy(a,b) \
  99     (GL_LINK_WARNING ("stpcpy is unportable - " \
 100                       "use gnulib module stpcpy for portability"), \
 101      stpcpy (a, b))
 102 #endif
 103
 104 /* Copy no more than N bytes of SRC to DST, returning a pointer past the
 105    last non-NUL byte written into DST.  */
 106 #if @GNULIB_STPNCPY@
 107 # if ! @HAVE_STPNCPY@
 108 #  define stpncpy gnu_stpncpy
 109 extern char *stpncpy (char *__restrict __dst, char const *__restrict __src,
 110                       size_t __n);
 111 # endif
 112 #elif defined GNULIB_POSIXCHECK
 113 # undef stpncpy
 114 # define stpncpy(a,b,n) \
 115     (GL_LINK_WARNING ("stpncpy is unportable - " \
 116                       "use gnulib module stpncpy for portability"), \
 117      stpncpy (a, b, n))
 118 #endif
 119
 120 /* Compare strings S1 and S2, ignoring case, returning less than, equal to or
 121    greater than zero if S1 is lexicographically less than, equal to or greater
 122    than S2.
 123    Note: This function does not work in multibyte locales.  */
 124 #if ! @HAVE_STRCASECMP@
 125 extern int strcasecmp (char const *s1, char const *s2);
 126 #endif
 127 #if defined GNULIB_POSIXCHECK
 128 /* strcasecmp() does not work with multibyte strings:
 129    POSIX says that it operates on "strings", and "string" in POSIX is defined
 130    as a sequence of bytes, not of characters.   */
 131 # undef strcasecmp
 132 # define strcasecmp(a,b) \
 133     (GL_LINK_WARNING ("strcasecmp cannot work correctly on character strings " \
 134                       "in multibyte locales - " \
 135                       "use mbscasecmp if you care about " \
 136                       "internationalization, or use c_strcasecmp (from " \
 137                       "gnulib module c-strcase) if you want a locale " \
 138                       "independent function"), \
 139      strcasecmp (a, b))
 140 #endif
 141
 142 /* Compare no more than N bytes of strings S1 and S2, ignoring case,
 143    returning less than, equal to or greater than zero if S1 is
 144    lexicographically less than, equal to or greater than S2.
 145    Note: This function cannot work correctly in multibyte locales.  */
 146 #if ! @HAVE_DECL_STRNCASECMP@
 147 extern int strncasecmp (char const *s1, char const *s2, size_t n);
 148 #endif
 149 #if defined GNULIB_POSIXCHECK
 150 /* strncasecmp() does not work with multibyte strings:
 151    POSIX says that it operates on "strings", and "string" in POSIX is defined
 152    as a sequence of bytes, not of characters.  */
 153 # undef strncasecmp
 154 # define strncasecmp(a,b,n) \
 155     (GL_LINK_WARNING ("strncasecmp cannot work correctly on character " \
 156                       "strings in multibyte locales - " \
 157                       "use mbsncasecmp or mbspcasecmp if you care about " \
 158                       "internationalization, or use c_strncasecmp (from " \
 159                       "gnulib module c-strcase) if you want a locale " \
 160                       "independent function"), \
 161      strncasecmp (a, b, n))
 162 #endif
 163
 164 #if defined GNULIB_POSIXCHECK
 165 /* strchr() does not work with multibyte strings if the locale encoding is
 166    GB18030 and the character to be searched is a digit.  */
 167 # undef strchr
 168 # define strchr(s,c) \
 169     (GL_LINK_WARNING ("strchr cannot work correctly on character strings " \
 170                       "in some multibyte locales - " \
 171                       "use mbschr if you care about internationalization"), \
 172      strchr (s, c))
 173 #endif
 174
 175 /* Find the first occurrence of C in S or the final NUL byte.  */
 176 #if @GNULIB_STRCHRNUL@
 177 # if ! @HAVE_STRCHRNUL@
 178 extern char *strchrnul (char const *__s, int __c_in);
 179 # endif
 180 #elif defined GNULIB_POSIXCHECK
 181 # undef strchrnul
 182 # define strchrnul(a,b) \
 183     (GL_LINK_WARNING ("strchrnul is unportable - " \
 184                       "use gnulib module strchrnul for portability"), \
 185      strchrnul (a, b))
 186 #endif
 187
 188 /* Duplicate S, returning an identical malloc'd string.  */
 189 #if @GNULIB_STRDUP@
 190 # if ! @HAVE_DECL_STRDUP@ && ! defined strdup
 191 extern char *strdup (char const *__s);
 192 # endif
 193 #elif defined GNULIB_POSIXCHECK
 194 # undef strdup
 195 # define strdup(a) \
 196     (GL_LINK_WARNING ("strdup is unportable - " \
 197                       "use gnulib module strdup for portability"), \
 198      strdup (a))
 199 #endif
 200
 201 /* Return a newly allocated copy of at most N bytes of STRING.  */
 202 #if @GNULIB_STRNDUP@
 203 # if ! @HAVE_STRNDUP@
 204 #  undef strndup
 205 #  define strndup rpl_strndup
 206 # endif
 207 # if ! @HAVE_STRNDUP@ || ! @HAVE_DECL_STRNDUP@
 208 extern char *strndup (char const *__string, size_t __n);
 209 # endif
 210 #elif defined GNULIB_POSIXCHECK
 211 # undef strndup
 212 # define strndup(a,n) \
 213     (GL_LINK_WARNING ("strndup is unportable - " \
 214                       "use gnulib module strndup for portability"), \
 215      strndup (a, n))
 216 #endif
 217
 218 /* Find the length (number of bytes) of STRING, but scan at most
 219    MAXLEN bytes.  If no '\0' terminator is found in that many bytes,
 220    return MAXLEN.  */
 221 #if @GNULIB_STRNLEN@
 222 # if ! @HAVE_DECL_STRNLEN@
 223 extern size_t strnlen (char const *__string, size_t __maxlen);
 224 # endif
 225 #elif defined GNULIB_POSIXCHECK
 226 # undef strnlen
 227 # define strnlen(a,n) \
 228     (GL_LINK_WARNING ("strnlen is unportable - " \
 229                       "use gnulib module strnlen for portability"), \
 230      strnlen (a, n))
 231 #endif
 232
 233 #if defined GNULIB_POSIXCHECK
 234 /* strcspn() assumes the second argument is a list of single-byte characters.
 235    Even in this simple case, it does not work with multibyte strings if the
 236    locale encoding is GB18030 and one of the characters to be searched is a
 237    digit.  */
 238 # undef strcspn
 239 # define strcspn(s,a) \
 240     (GL_LINK_WARNING ("strcspn cannot work correctly on character strings " \
 241                       "in multibyte locales - " \
 242                       "use mbscspn if you care about internationalization"), \
 243      strcspn (s, a))
 244 #endif
 245
 246 /* Find the first occurrence in S of any character in ACCEPT.  */
 247 #if @GNULIB_STRPBRK@
 248 # if ! @HAVE_STRPBRK@
 249 extern char *strpbrk (char const *__s, char const *__accept);
 250 # endif
 251 # if defined GNULIB_POSIXCHECK
 252 /* strpbrk() assumes the second argument is a list of single-byte characters.
 253    Even in this simple case, it does not work with multibyte strings if the
 254    locale encoding is GB18030 and one of the characters to be searched is a
 255    digit.  */
 256 #  undef strpbrk
 257 #  define strpbrk(s,a) \
 258      (GL_LINK_WARNING ("strpbrk cannot work correctly on character strings " \
 259                        "in multibyte locales - " \
 260                        "use mbspbrk if you care about internationalization"), \
 261       strpbrk (s, a))
 262 # endif
 263 #elif defined GNULIB_POSIXCHECK
 264 # undef strpbrk
 265 # define strpbrk(s,a) \
 266     (GL_LINK_WARNING ("strpbrk is unportable - " \
 267                       "use gnulib module strpbrk for portability"), \
 268      strpbrk (s, a))
 269 #endif
 270
 271 #if defined GNULIB_POSIXCHECK
 272 /* strspn() assumes the second argument is a list of single-byte characters.
 273    Even in this simple case, it cannot work with multibyte strings.  */
 274 # undef strspn
 275 # define strspn(s,a) \
 276     (GL_LINK_WARNING ("strspn cannot work correctly on character strings " \
 277                       "in multibyte locales - " \
 278                       "use mbsspn if you care about internationalization"), \
 279      strspn (s, a))
 280 #endif
 281
 282 #if defined GNULIB_POSIXCHECK
 283 /* strrchr() does not work with multibyte strings if the locale encoding is
 284    GB18030 and the character to be searched is a digit.  */
 285 # undef strrchr
 286 # define strrchr(s,c) \
 287     (GL_LINK_WARNING ("strrchr cannot work correctly on character strings " \
 288                       "in some multibyte locales - " \
 289                       "use mbsrchr if you care about internationalization"), \
 290      strrchr (s, c))
 291 #endif
 292
 293 /* Search the next delimiter (char listed in DELIM) starting at *STRINGP.
 294    If one is found, overwrite it with a NUL, and advance *STRINGP
 295    to point to the next char after it.  Otherwise, set *STRINGP to NULL.
 296    If *STRINGP was already NULL, nothing happens.
 297    Return the old value of *STRINGP.
 298
 299    This is a variant of strtok() that is multithread-safe and supports
 300    empty fields.
 301
 302    Caveat: It modifies the original string.
 303    Caveat: These functions cannot be used on constant strings.
 304    Caveat: The identity of the delimiting character is lost.
 305    Caveat: It doesn't work with multibyte strings unless all of the delimiter
 306            characters are ASCII characters < 0x30.
 307
 308    See also strtok_r().  */
 309 #if @GNULIB_STRSEP@
 310 # if ! @HAVE_STRSEP@
 311 extern char *strsep (char **__restrict __stringp, char const *__restrict __delim);
 312 # endif
 313 # if defined GNULIB_POSIXCHECK
 314 #  undef strsep
 315 #  define strsep(s,d) \
 316      (GL_LINK_WARNING ("strsep cannot work correctly on character strings " \
 317                        "in multibyte locales - " \
 318                        "use mbssep if you care about internationalization"), \
 319       strsep (s, d))
 320 # endif
 321 #elif defined GNULIB_POSIXCHECK
 322 # undef strsep
 323 # define strsep(s,d) \
 324     (GL_LINK_WARNING ("strsep is unportable - " \
 325                       "use gnulib module strsep for portability"), \
 326      strsep (s, d))
 327 #endif
 328
 329 #if defined GNULIB_POSIXCHECK
 330 /* strstr() does not work with multibyte strings if the locale encoding is
 331    different from UTF-8:
 332    POSIX says that it operates on "strings", and "string" in POSIX is defined
 333    as a sequence of bytes, not of characters.  */
 334 # undef strstr
 335 # define strstr(a,b) \
 336     (GL_LINK_WARNING ("strstr cannot work correctly on character strings " \
 337                       "in most multibyte locales - " \
 338                       "use mbsstr if you care about internationalization"), \
 339      strstr (a, b))
 340 #endif
 341
 342 /* Find the first occurrence of NEEDLE in HAYSTACK, using case-insensitive
 343    comparison.  */
 344 #if ! @HAVE_STRCASESTR@
 345 extern char *strcasestr (const char *haystack, const char *needle);
 346 #endif
 347 #if defined GNULIB_POSIXCHECK
 348 /* strcasestr() does not work with multibyte strings:
 349    It is a glibc extension, and glibc implements it only for unibyte
 350    locales.  */
 351 # undef strcasestr
 352 # define strcasestr(a,b) \
 353     (GL_LINK_WARNING ("strcasestr does work correctly on character strings " \
 354                       "in multibyte locales - " \
 355                       "use mbscasestr if you care about " \
 356                       "internationalization, or use c-strcasestr if you want " \
 357                       "a locale independent function"), \
 358      strcasestr (a, b))
 359 #endif
 360
 361 /* Parse S into tokens separated by characters in DELIM.
 362    If S is NULL, the saved pointer in SAVE_PTR is used as
 363    the next starting point.  For example:
 364         char s[] = "-abc-=-def";
 365         char *sp;
 366         x = strtok_r(s, "-", &sp);      // x = "abc", sp = "=-def"
 367         x = strtok_r(NULL, "-=", &sp);  // x = "def", sp = NULL
 368         x = strtok_r(NULL, "=", &sp);   // x = NULL
 369                 // s = "abc\0-def\0"
 370
 371    This is a variant of strtok() that is multithread-safe.
 372
 373    For the POSIX documentation for this function, see:
 374    http://www.opengroup.org/susv3xsh/strtok.html
 375
 376    Caveat: It modifies the original string.
 377    Caveat: These functions cannot be used on constant strings.
 378    Caveat: The identity of the delimiting character is lost.
 379    Caveat: It doesn't work with multibyte strings unless all of the delimiter
 380            characters are ASCII characters < 0x30.
 381
 382    See also strsep().  */
 383 #if @GNULIB_STRTOK_R@
 384 # if ! @HAVE_DECL_STRTOK_R@
 385 extern char *strtok_r (char *__restrict s, char const *__restrict delim,
 386                        char **__restrict save_ptr);
 387 # endif
 388 # if defined GNULIB_POSIXCHECK
 389 #  undef strtok_r
 390 #  define strtok_r(s,d,p) \
 391      (GL_LINK_WARNING ("strtok_r cannot work correctly on character strings " \
 392                        "in multibyte locales - " \
 393                        "use mbstok_r if you care about internationalization"), \
 394       strtok_r (s, d, p))
 395 # endif
 396 #elif defined GNULIB_POSIXCHECK
 397 # undef strtok_r
 398 # define strtok_r(s,d,p) \
 399     (GL_LINK_WARNING ("strtok_r is unportable - " \
 400                       "use gnulib module strtok_r for portability"), \
 401      strtok_r (s, d, p))
 402 #endif
 403
 404
 405 /* The following functions are not specified by POSIX.  They are gnulib
 406    extensions.  */
 407
 408 #if @GNULIB_MBSLEN@
 409 /* Return the number of multibyte characters in the character string STRING.
 410    This considers multibyte characters, unlike strlen, which counts bytes.  */
 411 extern size_t mbslen (const char *string);
 412 #endif
 413
 414 #if @GNULIB_MBSNLEN@
 415 /* Return the number of multibyte characters in the character string starting
 416    at STRING and ending at STRING + LEN.  */
 417 extern size_t mbsnlen (const char *string, size_t len);
 418 #endif
 419
 420 #if @GNULIB_MBSCHR@
 421 /* Locate the first single-byte character C in the character string STRING,
 422    and return a pointer to it.  Return NULL if C is not found in STRING.
 423    Unlike strchr(), this function works correctly in multibyte locales with
 424    encodings such as GB18030.  */
 425 # define mbschr rpl_mbschr /* avoid collision with HP-UX function */
 426 extern char * mbschr (const char *string, int c);
 427 #endif
 428
 429 #if @GNULIB_MBSRCHR@
 430 /* Locate the last single-byte character C in the character string STRING,
 431    and return a pointer to it.  Return NULL if C is not found in STRING.
 432    Unlike strrchr(), this function works correctly in multibyte locales with
 433    encodings such as GB18030.  */
 434 # define mbsrchr rpl_mbsrchr /* avoid collision with HP-UX function */
 435 extern char * mbsrchr (const char *string, int c);
 436 #endif
 437
 438 #if @GNULIB_MBSSTR@
 439 /* Find the first occurrence of the character string NEEDLE in the character
 440    string HAYSTACK.  Return NULL if NEEDLE is not found in HAYSTACK.
 441    Unlike strstr(), this function works correctly in multibyte locales with
 442    encodings different from UTF-8.  */
 443 extern char * mbsstr (const char *haystack, const char *needle);
 444 #endif
 445
 446 #if @GNULIB_MBSCASECMP@
 447 /* Compare the character strings S1 and S2, ignoring case, returning less than,
 448    equal to or greater than zero if S1 is lexicographically less than, equal to
 449    or greater than S2.
 450    Note: This function may, in multibyte locales, return 0 for strings of
 451    different lengths!
 452    Unlike strcasecmp(), this function works correctly in multibyte locales.  */
 453 extern int mbscasecmp (const char *s1, const char *s2);
 454 #endif
 455
 456 #if @GNULIB_MBSNCASECMP@
 457 /* Compare the initial segment of the character string S1 consisting of at most
 458    N characters with the initial segment of the character string S2 consisting
 459    of at most N characters, ignoring case, returning less than, equal to or
 460    greater than zero if the initial segment of S1 is lexicographically less
 461    than, equal to or greater than the initial segment of S2.
 462    Note: This function may, in multibyte locales, return 0 for initial segments
 463    of different lengths!
 464    Unlike strncasecmp(), this function works correctly in multibyte locales.
 465    But beware that N is not a byte count but a character count!  */
 466 extern int mbsncasecmp (const char *s1, const char *s2, size_t n);
 467 #endif
 468
 469 #if @GNULIB_MBSPCASECMP@
 470 /* Compare the initial segment of the character string STRING consisting of
 471    at most mbslen (PREFIX) characters with the character string PREFIX,
 472    ignoring case, returning less than, equal to or greater than zero if this
 473    initial segment is lexicographically less than, equal to or greater than
 474    PREFIX.
 475    Note: This function may, in multibyte locales, return 0 if STRING is of
 476    smaller length than PREFIX!
 477    Unlike strncasecmp(), this function works correctly in multibyte
 478    locales.  */
 479 extern char * mbspcasecmp (const char *string, const char *prefix);
 480 #endif
 481
 482 #if @GNULIB_MBSCASESTR@
 483 /* Find the first occurrence of the character string NEEDLE in the character
 484    string HAYSTACK, using case-insensitive comparison.
 485    Note: This function may, in multibyte locales, return success even if
 486    strlen (haystack) < strlen (needle) !
 487    Unlike strcasestr(), this function works correctly in multibyte locales.  */
 488 extern char * mbscasestr (const char *haystack, const char *needle);
 489 #endif
 490
 491 #if @GNULIB_MBSCSPN@
 492 /* Find the first occurrence in the character string STRING of any character
 493    in the character string ACCEPT.  Return the number of bytes from the
 494    beginning of the string to this occurrence, or to the end of the string
 495    if none exists.
 496    Unlike strcspn(), this function works correctly in multibyte locales.  */
 497 extern size_t mbscspn (const char *string, const char *accept);
 498 #endif
 499
 500 #if @GNULIB_MBSPBRK@
 501 /* Find the first occurrence in the character string STRING of any character
 502    in the character string ACCEPT.  Return the pointer to it, or NULL if none
 503    exists.
 504    Unlike strpbrk(), this function works correctly in multibyte locales.  */
 505 # define mbspbrk rpl_mbspbrk /* avoid collision with HP-UX function */
 506 extern char * mbspbrk (const char *string, const char *accept);
 507 #endif
 508
 509 #if @GNULIB_MBSSPN@
 510 /* Find the first occurrence in the character string STRING of any character
 511    not in the character string REJECT.  Return the number of bytes from the
 512    beginning of the string to this occurrence, or to the end of the string
 513    if none exists.
 514    Unlike strspn(), this function works correctly in multibyte locales.  */
 515 extern size_t mbsspn (const char *string, const char *reject);
 516 #endif
 517
 518 #if @GNULIB_MBSSEP@
 519 /* Search the next delimiter (multibyte character listed in the character
 520    string DELIM) starting at the character string *STRINGP.
 521    If one is found, overwrite it with a NUL, and advance *STRINGP to point
 522    to the next multibyte character after it.  Otherwise, set *STRINGP to NULL.
 523    If *STRINGP was already NULL, nothing happens.
 524    Return the old value of *STRINGP.
 525
 526    This is a variant of mbstok_r() that supports empty fields.
 527
 528    Caveat: It modifies the original string.
 529    Caveat: These functions cannot be used on constant strings.
 530    Caveat: The identity of the delimiting character is lost.
 531
 532    See also mbstok_r().  */
 533 extern char * mbssep (char **stringp, const char *delim);
 534 #endif
 535
 536 #if @GNULIB_MBSTOK_R@
 537 /* Parse the character string STRING into tokens separated by characters in
 538    the character string DELIM.
 539    If STRING is NULL, the saved pointer in SAVE_PTR is used as
 540    the next starting point.  For example:
 541         char s[] = "-abc-=-def";
 542         char *sp;
 543         x = mbstok_r(s, "-", &sp);      // x = "abc", sp = "=-def"
 544         x = mbstok_r(NULL, "-=", &sp);  // x = "def", sp = NULL
 545         x = mbstok_r(NULL, "=", &sp);   // x = NULL
 546                 // s = "abc\0-def\0"
 547
 548    Caveat: It modifies the original string.
 549    Caveat: These functions cannot be used on constant strings.
 550    Caveat: The identity of the delimiting character is lost.
 551
 552    See also mbssep().  */
 553 extern char * mbstok_r (char *string, const char *delim, char **save_ptr);
 554 #endif
 555
 556 /* Map any int, typically from errno, into an error message.  */
 557 #if @GNULIB_STRERROR@
 558 # if @REPLACE_STRERROR@
 559 #  undef strerror
 560 #  define strerror rpl_strerror
 561 # endif
 562 # if !@HAVE_DECL_STRERROR@ || @REPLACE_STRERROR@
 563 extern char *strerror (int);
 564 # endif
 565 #elif defined GNULIB_POSIXCHECK
 566 # undef strerror
 567 # define strerror(e) \
 568     (GL_LINK_WARNING ("strerror is unportable - " \
 569                       "use gnulib module strerror to guarantee non-NULL result"), \
 570      strerror (e))
 571 #endif
 572
 573
 574 #ifdef __cplusplus
 575 }
 576 #endif
 577
 578 #endif /* _GL_STRING_H */
 579 #endif /* _GL_STRING_H */