lib/c-strstr.h

   1 /* Searching in a string.
   2    Copyright (C) 2001-2003, 2006, 2009-2024 Free Software Foundation, Inc.
   3
   4    This file is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU Lesser General Public License as
   6    published by the Free Software Foundation, either version 3 of the
   7    License, or (at your option) any later version.
   8
   9    This file is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17
  18 /* The functions defined in this file assume a nearly ASCII compatible
  19    character set.  */
  20
  21
  22 #ifdef __cplusplus
  23 extern "C" {
  24 #endif
  25
  26 /* Find the first occurrence of NEEDLE in HAYSTACK.
  27    This function is safe to be called, even in a multibyte locale, if NEEDLE
  28      1. consists solely of printable ASCII characters excluding '\\' and '~'
  29         [this restriction is needed because of Shift_JIS and JOHAB]
  30         or of the control ASCII characters '\a' '\b' '\f' '\n' '\r' '\t' '\v'
  31         [this restriction is needed because of VISCII], and
  32      2. has at least length 2
  33         [this restriction is needed because of BIG5, BIG5-HKSCS, GBK, GB18030,
  34          Shift_JIS, JOHAB], and
  35      3. does not consist entirely of decimal digits, or has at least length 4
  36         [this restriction is needed because of GB18030].
  37    This function is also safe to be called, even in a multibyte locale, if
  38    HAYSTACK and NEEDLE are known to both consist solely of printable ASCII
  39    characters excluding '\\' and '~'.  */
  40 extern char *c_strstr (const char *haystack, const char *needle);
  41
  42 #ifdef __cplusplus
  43 }
  44 #endif