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Diffstat (limited to 'lib/memmem.c')
-rw-r--r-- | lib/memmem.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/lib/memmem.c b/lib/memmem.c new file mode 100644 index 000000000..1cbe629bd --- /dev/null +++ b/lib/memmem.c @@ -0,0 +1,49 @@ +/* Copyright (C) 1991,92,93,94,96,97,98,2000,2004,2007 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License along + with this program; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + +#include "config.h" + +#include <stddef.h> +#include <string.h> + +/* Return the first occurrence of NEEDLE in HAYSTACK. */ +void *xine_internal_memmem (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 (haystack_len < needle_len) + 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; +} |