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Diffstat (limited to 'ext/standard/strnatcmp.c')
| -rw-r--r-- | ext/standard/strnatcmp.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/ext/standard/strnatcmp.c b/ext/standard/strnatcmp.c new file mode 100644 index 0000000..face191 --- /dev/null +++ b/ext/standard/strnatcmp.c @@ -0,0 +1,189 @@ +/* -*- mode: c; c-file-style: "k&r" -*- + + Modified for PHP by Andrei Zmievski <andrei@ispi.net> + + strnatcmp.c -- Perform 'natural order' comparisons of strings in C. + Copyright (C) 2000 by Martin Pool <mbp@humbug.org.au> + + This software is provided 'as-is', without any express or implied + warranty. In no event will the authors be held liable for any damages + arising from the use of this software. + + Permission is granted to anyone to use this software for any purpose, + including commercial applications, and to alter it and redistribute it + freely, subject to the following restrictions: + + 1. The origin of this software must not be misrepresented; you must not + claim that you wrote the original software. If you use this software + in a product, an acknowledgment in the product documentation would be + appreciated but is not required. + 2. Altered source versions must be plainly marked as such, and must not be + misrepresented as being the original software. + 3. This notice may not be removed or altered from any source distribution. +*/ + +#include <ctype.h> +#include <string.h> +#include <assert.h> +#include <stdio.h> + +#include "php.h" +#include "php_string.h" + +#if defined(__GNUC__) +# define UNUSED __attribute__((__unused__)) +#else +# define UNUSED +#endif + +#if 0 +static char const *version UNUSED = + "$Id$"; +#endif +/* {{{ compare_right + */ +static int +compare_right(char const **a, char const *aend, char const **b, char const *bend) +{ + int bias = 0; + + /* The longest run of digits wins. That aside, the greatest + value wins, but we can't know that it will until we've scanned + both numbers to know that they have the same magnitude, so we + remember it in BIAS. */ + for(;; (*a)++, (*b)++) { + if ((*a == aend || !isdigit((int)(unsigned char)**a)) && + (*b == bend || !isdigit((int)(unsigned char)**b))) + return bias; + else if (*a == aend || !isdigit((int)(unsigned char)**a)) + return -1; + else if (*b == bend || !isdigit((int)(unsigned char)**b)) + return +1; + else if (**a < **b) { + if (!bias) + bias = -1; + } else if (**a > **b) { + if (!bias) + bias = +1; + } + } + + return 0; +} +/* }}} */ + +/* {{{ compare_left + */ +static int +compare_left(char const **a, char const *aend, char const **b, char const *bend) +{ + /* Compare two left-aligned numbers: the first to have a + different value wins. */ + for(;; (*a)++, (*b)++) { + if ((*a == aend || !isdigit((int)(unsigned char)**a)) && + (*b == bend || !isdigit((int)(unsigned char)**b))) + return 0; + else if (*a == aend || !isdigit((int)(unsigned char)**a)) + return -1; + else if (*b == bend || !isdigit((int)(unsigned char)**b)) + return +1; + else if (**a < **b) + return -1; + else if (**a > **b) + return +1; + } + + return 0; +} +/* }}} */ + +/* {{{ strnatcmp_ex + */ +PHPAPI int strnatcmp_ex(char const *a, size_t a_len, char const *b, size_t b_len, int fold_case) +{ + unsigned char ca, cb; + char const *ap, *bp; + char const *aend = a + a_len, + *bend = b + b_len; + int fractional, result; + short leading = 1; + + if (a_len == 0 || b_len == 0) + return a_len - b_len; + + ap = a; + bp = b; + while (1) { + ca = *ap; cb = *bp; + + /* skip over leading zeros */ + while (leading && ca == '0' && (ap+1 < aend) && isdigit(*(ap+1))) { + ca = *++ap; + } + + while (leading && cb == '0' && (bp+1 < bend) && isdigit(*(bp+1))) { + cb = *++bp; + } + + leading = 0; + + /* Skip consecutive whitespace */ + while (isspace((int)(unsigned char)ca)) { + ca = *++ap; + } + + while (isspace((int)(unsigned char)cb)) { + cb = *++bp; + } + + /* process run of digits */ + if (isdigit((int)(unsigned char)ca) && isdigit((int)(unsigned char)cb)) { + fractional = (ca == '0' || cb == '0'); + + if (fractional) + result = compare_left(&ap, aend, &bp, bend); + else + result = compare_right(&ap, aend, &bp, bend); + + if (result != 0) + return result; + else if (ap == aend && bp == bend) + /* End of the strings. Let caller sort them out. */ + return 0; + else { + /* Keep on comparing from the current point. */ + ca = *ap; cb = *bp; + } + } + + if (fold_case) { + ca = toupper((int)(unsigned char)ca); + cb = toupper((int)(unsigned char)cb); + } + + if (ca < cb) + return -1; + else if (ca > cb) + return +1; + + ++ap; ++bp; + if (ap >= aend && bp >= bend) + /* The strings compare the same. Perhaps the caller + will want to call strcmp to break the tie. */ + return 0; + else if (ap >= aend) + return -1; + else if (bp >= bend) + return 1; + } +} +/* }}} */ + +/* + * Local variables: + * tab-width: 4 + * c-basic-offset: 4 + * End: + * vim600: sw=4 ts=4 fdm=marker + * vim<600: sw=4 ts=4 + */ |