From b21b9f1de313acb5550c070911ae58c735cdb451 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ren=C3=A9=20Scharfe?= Date: Fri, 7 Sep 2007 00:32:54 +0200 Subject: add memmem() memmem() is a nice GNU extension for searching a length limited string in another one. This compat version is based on the version found in glibc 2.2 (GPL 2); I only removed the optimization of checking the first char by hand, and generally tried to keep the code simple. We can add it back if memcmp shows up high in a profile, but for now I prefer to keep it (almost trivially) simple. Since I don't really know which platforms beside those with a glibc have their own memmem(), I used a heuristic: if NO_STRCASESTR is set, then NO_MEMMEM is set, too. Signed-off-by: Rene Scharfe Signed-off-by: Junio C Hamano --- compat/memmem.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 compat/memmem.c (limited to 'compat') diff --git a/compat/memmem.c b/compat/memmem.c new file mode 100644 index 0000000000..cd0d877364 --- /dev/null +++ b/compat/memmem.c @@ -0,0 +1,29 @@ +#include "../git-compat-util.h" + +void *gitmemmem(const void *haystack, size_t haystack_len, + const void *needle, size_t needle_len) +{ + const char *begin = haystack; + const char *last_possible = begin + haystack_len - needle_len; + + /* + * The first occurrence of the empty string is deemed to occur at + * the beginning of the string. + */ + if (needle_len == 0) + return (void *)begin; + + /* + * Sanity check, otherwise the loop might search through the whole + * memory. + */ + if (haystack_len < needle_len) + return NULL; + + for (; begin <= last_possible; begin++) { + if (!memcmp(begin, needle, needle_len)) + return (void *)begin; + } + + return NULL; +} -- cgit v1.2.3