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- /* Copyright (c) 2000, 2021, Oracle and/or its affiliates.
- 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, version 2.0,
- as published by the Free Software Foundation.
-
- This program is also distributed with certain software (including
- but not limited to OpenSSL) that is licensed under separate terms,
- as designated in a particular file or component or in included license
- documentation. The authors of MySQL hereby grant you an additional
- permission to link the program and your derivative works with the
- separately licensed software that they have included with MySQL.
-
- Without limiting anything contained in the foregoing, this file,
- which is part of C Driver for MySQL (Connector/C), is also subject to the
- Universal FOSS Exception, version 1.0, a copy of which can be found at
- http://oss.oracle.com/licenses/universal-foss-exception.
-
- 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, version 2.0, 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 <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
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