1 /* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Library General Public License as
6 published by the Free Software Foundation; either version 2 of the
7 License, or (at your option) any later version.
9 The GNU C Library 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 GNU
12 Library General Public License for more details.
14 You should have received a copy of the GNU Library General Public
15 License along with the GNU C Library; see the file COPYING.LIB. If
16 not, write to the Free Software Foundation, Inc., 59 Temple Place -
17 Suite 330, Boston, MA 02111-1307, USA.
19 This file was modified slightly by Ian Lance Taylor, May 1992, for
24 /* Return the first ocurrence of NEEDLE in HAYSTACK. */
26 strstr (haystack, needle)
27 const char *const haystack;
28 const char *const needle;
30 register const char *const needle_end = strchr(needle, '\0');
31 register const char *const haystack_end = strchr(haystack, '\0');
32 register const size_t needle_len = needle_end - needle;
33 register const size_t needle_last = needle_len - 1;
34 register const char *begin;
37 return (char *) haystack_end;
38 if ((size_t) (haystack_end - haystack) < needle_len)
41 for (begin = &haystack[needle_last]; begin < haystack_end; ++begin)
43 register const char *n = &needle[needle_last];
44 register const char *h = begin;
48 while (--n >= needle && --h >= haystack);