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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 18:00:34 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 18:00:34 +0000 |
commit | 3f619478f796eddbba6e39502fe941b285dd97b1 (patch) | |
tree | e2c7b5777f728320e5b5542b6213fd3591ba51e2 /mysys/my_memmem.c | |
parent | Initial commit. (diff) | |
download | mariadb-3f619478f796eddbba6e39502fe941b285dd97b1.tar.xz mariadb-3f619478f796eddbba6e39502fe941b285dd97b1.zip |
Adding upstream version 1:10.11.6.upstream/1%10.11.6upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'mysys/my_memmem.c')
-rw-r--r-- | mysys/my_memmem.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/mysys/my_memmem.c b/mysys/my_memmem.c new file mode 100644 index 00000000..98b45fed --- /dev/null +++ b/mysys/my_memmem.c @@ -0,0 +1,84 @@ +/* Copyright (c) 2000, 2006, 2007 MySQL AB + Use is subject to license terms + + 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; version 2 of the License. + + 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 02110-1335 USA */ + +#include <my_global.h> +#include <m_string.h> + +/* + my_memmem, port of a GNU extension. + + Returns a pointer to the beginning of the substring, needle, or NULL if the + substring is not found in haystack. +*/ + +void *my_memmem(const void *haystack, size_t haystacklen, + const void *needle, size_t needlelen) +{ + const unsigned char *cursor; + const unsigned char *last_possible_needle_location = + (unsigned char *)haystack + haystacklen - needlelen; + + /* Easy answers */ + if (needlelen > haystacklen) return(NULL); + if (needle == NULL) return(NULL); + if (haystack == NULL) return(NULL); + if (needlelen == 0) return(NULL); + if (haystacklen == 0) return(NULL); + + for (cursor = haystack; cursor <= last_possible_needle_location; cursor++) { + if (memcmp(needle, cursor, needlelen) == 0) { + return((void *) cursor); + } + } + return(NULL); +} + + + +#ifdef MAIN +#include <assert.h> + +int main(int argc, char *argv[]) { + char haystack[10], needle[3]; + + memmove(haystack, "0123456789", 10); + + memmove(needle, "no", 2); + assert(my_memmem(haystack, 10, needle, 2) == NULL); + + memmove(needle, "345", 3); + assert(my_memmem(haystack, 10, needle, 3) != NULL); + + memmove(needle, "789", 3); + assert(my_memmem(haystack, 10, needle, 3) != NULL); + assert(my_memmem(haystack, 9, needle, 3) == NULL); + + memmove(needle, "012", 3); + assert(my_memmem(haystack, 10, needle, 3) != NULL); + assert(my_memmem(NULL, 10, needle, 3) == NULL); + + assert(my_memmem(NULL, 10, needle, 3) == NULL); + assert(my_memmem(haystack, 0, needle, 3) == NULL); + assert(my_memmem(haystack, 10, NULL, 3) == NULL); + assert(my_memmem(haystack, 10, needle, 0) == NULL); + + assert(my_memmem(haystack, 1, needle, 3) == NULL); + + printf("success\n"); + return(0); +} + +#endif |