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Diffstat (limited to '')
| -rw-r--r-- | src/wchar/wcsncasecmp.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/src/wchar/wcsncasecmp.c b/src/wchar/wcsncasecmp.c new file mode 100644 index 0000000..69305ea --- /dev/null +++ b/src/wchar/wcsncasecmp.c @@ -0,0 +1,52 @@ +/** + * 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 <wchar.h> +/* TODO #include <wctype.h> */ + + + +/** + * Compare two strings alphabetically in a case insensitive manner. + * Be aware, only ASCII characters are case insensitive, non-ASCII + * characters are case sensitive. + * + * This is a GNU-compliant slibc extension. + * + * @param a A negative 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 wcsncasecmp(const wchar_t* a, const wchar_t* b, size_t length) +{ + wchar_t c1, c2; + for (; length--; a++, b++) + if (*a != *b) + { + c1 = iswalpha(*a) ? towlower(*a) : *a; + c2 = iswalpha(*b) ? towlower(*b) : *b; + if (c1 < c2) return -1; + if (c1 > c2) return +1; + } + else if (!*a && !*b) return 0; + else if (!*a) return -1; + else if (!*b) return +1; + return 0; +} + |