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Diffstat (limited to '')
| -rw-r--r-- | src/string/strstr.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/src/string/strstr.c b/src/string/strstr.c new file mode 100644 index 0000000..a7e490a --- /dev/null +++ b/src/string/strstr.c @@ -0,0 +1,179 @@ +/** + * slibc — Yet another C library + * Copyright © 2015 Mattias Andrée (maandree@member.fsf.org) + * + * 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 3 of the License, 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, see <http://www.gnu.org/licenses/>. + */ +#include <string.h> +#include <stddef.h> +#include <inttypes.h> + + + +/** + * Finds the first occurrence of a substring. + * This search is case sensitive. + * + * @param haystack The string to search. + * @param needle The sought after substring. + * @return Pointer to the first occurrence of the + * substring, `NULL` if not found. + */ +char* strstr(const char* haystack, const char* needle) +{ + return memmem(haystack, strlen(haystack), needle, strlen(needle)); +} + + +/** + * Finds the first occurrence of a substring. + * This search is case insensitive. + * + * @param haystack The string to search. + * @param needle The sought after substring. + * @return Pointer to the first occurrence of the + * substring, `NULL` if not found. + */ +char* strcasestr(const char* haystack, const char* needle) +{ + return memcasemem(haystack, strlen(haystack), needle, strlen(needle)); +} + + +/** + * Finds the first occurrence of a substring. + * This search is case sensitive. + * + * This is a slibc extension added for because it was useful + * in implementing slibc itself. + * + * @param haystack The string to search. + * @param needle The sought after substring. + * @param maxlen The maximum number of character to search. + * @return Pointer to the first occurrence of the + * substring, `NULL` if not found. + */ +char* strnstr(const char* haystack, const char* needle, size_t maxlen) +{ + return memmem(haystack, strnlen(haystack, maxlen), needle, strlen(needle)); +} + + +/** + * Finds the first occurrence of a substring. + * This search is case insensitive. + * + * This is a slibc extension added for completeness. + * + * @param haystack The string to search. + * @param needle The sought after substring. + * @param maxlen The maximum number of character to search. + * @return Pointer to the first occurrence of the + * substring, `NULL` if not found. + */ +char* strncasestr(const char* haystack, const char* needle, size_t maxlen) +{ + return memcasemem(haystack, strnlen(haystack, maxlen), needle, strlen(needle)); +} + + +/** + * Finds the first occurrence of a substring. + * This search is case sensitive. + * It must already be known that such a substring exists. + * + * This is a slibc extension. + * + * @param haystack The string to search. + * @param needle The sought after substring. + * @return Pointer to the first occurrence of the substring. + */ +char* rawstrstr(const char* haystack, const char* needle) +{ + return memmem(haystack, SIZE_MAX, needle, strlen(needle)); +} + + +/** + * Finds the first occurrence of a substring. + * This search is case insensitive. + * It must already be known that such a substring exists. + * + * This is a slibc extension. + * + * @param haystack The string to search. + * @param needle The sought after substring. + * @return Pointer to the first occurrence of the substring. + */ +char* rawstrcasestr(const char* haystack, const char* needle) +{ + return memcasemem(haystack, SIZE_MAX, needle, strlen(needle)); +} + + +/** + * Finds the first occurrence of a substring + * This search is case sensitive. + * + * This is a GNU-compliant slibc extension. It was useful + * in implementing slibc itself. + * + * @param haystack The string to search. + * @param haystack_length The number of character to search. + * @param needle The sought after substring. + * @param needle_length The length of `needle`. + * @return Pointer to the first occurrence of + * the substring, `NULL` if not found. + */ +void* memmem(const void* __haystack, size_t haystack_length, + const void* __needle, size_t needle_length) +{ + const char* haystack = __haystack; + const char* needle = __needle; + if (haystack_length < needle_length) + return NULL; + if (haystack_length == needle_length) + return !memcmp(haystack, haystack_length, haystack_length) ? haystack : NULL; +#include "substring.h" +} + + +/** + * Finds the first occurrence of a substring + * This search is case insensitive. + * + * This is a slibc extension added because it was useful + * in implementing slibc itself. + * + * @param haystack The string to search. + * @param haystack_length The number of character to search. + * @param needle The sought after substring. + * @param needle_length The length of `needle`. + * @return Pointer to the first occurrence of + * the substring, `NULL` if not found. + */ +void* memcasemem(const void* __haystack, size_t haystack_length, + const void* __needle, size_t needle_length) +{ + const char* haystack = __haystack; + const char* needle = __needle; + if (haystack_length < needle_length) + return NULL; + if (haystack_length == needle_length) + return !memcasecmp(haystack, haystack_length, haystack_length) ? haystack : NULL; +#define CASE +#include "substring.h" +#undef CASE +} + |