diff options
Diffstat (limited to 'src/string')
| -rw-r--r-- | src/string/strcmp.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/src/string/strcmp.c b/src/string/strcmp.c new file mode 100644 index 0000000..966bb06 --- /dev/null +++ b/src/string/strcmp.c @@ -0,0 +1,122 @@ +/** + * 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 <strings.h> +#include <stddef.h> +#include <inttypes.h> +#include <ctype.h> + + + +/** + * Compare two memory segments alphabetically in a case sensitive manner. + * + * @param a A negetive value is returned if this is the lesser. + * @param b A positive value is returned if this is the lesser. + * @param size The size of the segments. + * @return Zero is returned if `a` and `b` are equal, otherwise, + * see the specifications for `a` and `b`. + */ +int memcmp(const void* a, const void* b, size_t size) +{ + const signed char* s1 = a; + const signed char* s2 = b; + while (size--) + if (*s1 == *s2) + s1++, s2++; + else + return (int)(*s1 - *s2); + return 0; +} + + +/** + * Compare two strings alphabetically in a case sensitive manner. + * + * @param a A negetive value is returned if this is the lesser. + * @param b A positive value is returned if this is the lesser. + * @return Zero is returned if `a` and `b` are equal, otherwise, + * see the specifications for `a` and `b`. + */ +int strcmp(const char* a, const char* b) +{ + size_t n = strlen(a); + size_t m = strlen(b); + return memcmp(a, b, (n < m ? n : m) + 1); +} + + +/** + * Compare two strings alphabetically in a case insensitive manner. + * Be aware, only ASCII characters are case insensitive, non-ASCII + * characters are case sensitive. + * + * @param a A negetive value is returned if this is the lesser. + * @param b A positive value is returned if this is the lesser. + * @return Zero is returned if `a` and `b` are equal, otherwise, + * see the specifications for `a` and `b`. + */ +int strcasecmp(const char* a, const char* b) +{ + return strncasecmp(a, b, SIZE_MAX); +} + + +/** + * Compare two strings alphabetically in a case sensitive manner. + * + * @param a A negetive value is returned if this is the lesser. + * @param b A positive value is returned if this is the lesser. + * @param length The maximum number of characters to compare. + * @return Zero is returned if `a` and `b` are equal, otherwise, + * see the specifications for `a` and `b`. + */ +int strncmp(const char* a, const char* b, size_t length) +{ + size_t n = strnlen(a, length); + size_t m = strnlen(b, length); + int r = memcmp(a, b, (n < m ? n : m)); + return r ? r : n == m ? 0 : n < m ? -1 : +1; +} + + +/** + * Compare two strings alphabetically in a case insensitive manner. + * Be aware, only ASCII characters are case insensitive, non-ASCII + * characters are case sensitive. + * + * @param a A negetive value is returned if this is the lesser. + * @param b A positive value is returned if this is the lesser. + * @param length The maximum number of characters to compare. + * @return Zero is returned if `a` and `b` are equal, otherwise, + * see the specifications for `a` and `b`. + */ +int strncasecmp(const char* a, const char* b, size_t length) +{ + int c1, c2; + for (; size--; a++, b++) + if (*a != *b) + { + c1 = isalpha(*a) ? tolower(*a) : (int)*a; + c2 = isalpha(*b) ? tolower(*b) : (int)*b; + if ((c1 -= c2)) + return c1; + } + return 0; +} + |