diff options
Diffstat (limited to 'contrib/apr/strings/apr_strnatcmp.c')
| -rw-r--r-- | contrib/apr/strings/apr_strnatcmp.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/contrib/apr/strings/apr_strnatcmp.c b/contrib/apr/strings/apr_strnatcmp.c new file mode 100644 index 0000000..0e960e8 --- /dev/null +++ b/contrib/apr/strings/apr_strnatcmp.c @@ -0,0 +1,149 @@ +/* -*- mode: c; c-file-style: "k&r" -*- + + 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 "apr_strings.h" +#include "apr_lib.h" /* for apr_is*() */ + +#if defined(__GNUC__) +# define UNUSED __attribute__((__unused__)) +#else +# define UNUSED +#endif + +/* based on "strnatcmp.c,v 1.6 2000/04/20 07:30:11 mbp Exp $" */ + +static int +compare_right(char const *a, char const *b) +{ + 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 (!apr_isdigit(*a) && !apr_isdigit(*b)) + break; + else if (!apr_isdigit(*a)) + return -1; + else if (!apr_isdigit(*b)) + return +1; + else if (*a < *b) { + if (!bias) + bias = -1; + } else if (*a > *b) { + if (!bias) + bias = +1; + } else if (!*a && !*b) + break; + } + + return bias; +} + + +static int +compare_left(char const *a, char const *b) +{ + /* Compare two left-aligned numbers: the first to have a + different value wins. */ + for (;; a++, b++) { + if (!apr_isdigit(*a) && !apr_isdigit(*b)) + break; + else if (!apr_isdigit(*a)) + return -1; + else if (!apr_isdigit(*b)) + return +1; + else if (*a < *b) + return -1; + else if (*a > *b) + return +1; + } + + return 0; +} + + +static int strnatcmp0(char const *a, char const *b, int fold_case) +{ + int ai, bi; + char ca, cb; + int fractional, result; + ai = bi = 0; + while (1) { + ca = a[ai]; cb = b[bi]; + + /* skip over leading spaces or zeros */ + while (apr_isspace(ca)) + ca = a[++ai]; + + while (apr_isspace(cb)) + cb = b[++bi]; + + /* process run of digits */ + if (apr_isdigit(ca) && apr_isdigit(cb)) { + fractional = (ca == '0' || cb == '0'); + + if (fractional) { + if ((result = compare_left(a+ai, b+bi)) != 0) + return result; + } else { + if ((result = compare_right(a+ai, b+bi)) != 0) + return result; + } + } + + if (!ca && !cb) { + /* The strings compare the same. Perhaps the caller + will want to call strcmp to break the tie. */ + return 0; + } + + if (fold_case) { + ca = apr_toupper(ca); + cb = apr_toupper(cb); + } + + if (ca < cb) + return -1; + else if (ca > cb) + return +1; + + ++ai; ++bi; + } +} + + + +APR_DECLARE(int) apr_strnatcmp(char const *a, char const *b) +{ + return strnatcmp0(a, b, 0); +} + + +/* Compare, recognizing numeric string and ignoring case. */ +APR_DECLARE(int) apr_strnatcasecmp(char const *a, char const *b) +{ + return strnatcmp0(a, b, 1); +} |
