diff options
author | Ulrich Drepper <drepper@redhat.com> | 2005-12-14 15:06:39 +0000 |
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committer | Ulrich Drepper <drepper@redhat.com> | 2005-12-14 15:06:39 +0000 |
commit | 9d13fb2413921c713f83efe331e8e4d219c62c6b (patch) | |
tree | 2d44d7ac45ab2d147eb8361bbff880c365aa8ad5 /string/memmem.c | |
parent | b6ab06cef4670e02756bcdd4d2c33a49369a4346 (diff) | |
download | glibc-9d13fb2413921c713f83efe331e8e4d219c62c6b.tar.gz |
Moved to csu/errno-loc.c.
Diffstat (limited to 'string/memmem.c')
-rw-r--r-- | string/memmem.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/string/memmem.c b/string/memmem.c new file mode 100644 index 0000000000..c40462104a --- /dev/null +++ b/string/memmem.c @@ -0,0 +1,58 @@ +/* Copyright (C) 1991,92,93,94,96,97,98,2000,2004 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <stddef.h> +#include <string.h> + +#ifndef _LIBC +# define __builtin_expect(expr, val) (expr) +#endif + +#undef memmem + +/* Return the first occurrence of NEEDLE in HAYSTACK. */ +void * +memmem (haystack, haystack_len, needle, needle_len) + const void *haystack; + size_t haystack_len; + const void *needle; + size_t needle_len; +{ + const char *begin; + const char *const last_possible + = (const char *) haystack + haystack_len - needle_len; + + if (needle_len == 0) + /* The first occurrence of the empty string is deemed to occur at + the beginning of the string. */ + return (void *) haystack; + + /* Sanity check, otherwise the loop might search through the whole + memory. */ + if (__builtin_expect (haystack_len < needle_len, 0)) + return NULL; + + for (begin = (const char *) haystack; begin <= last_possible; ++begin) + if (begin[0] == ((const char *) needle)[0] && + !memcmp ((const void *) &begin[1], + (const void *) ((const char *) needle + 1), + needle_len - 1)) + return (void *) begin; + + return NULL; +} |