diff options
author | Thomas Martitz <kugel@rockbox.org> | 2009-03-01 17:55:59 +0000 |
---|---|---|
committer | Thomas Martitz <kugel@rockbox.org> | 2009-03-01 17:55:59 +0000 |
commit | d13f1a485f0e35a6fbbd0a664f14acc3798d52a0 (patch) | |
tree | 22cacb27b6ab481c0bfc250120dde404320811f2 /firmware | |
parent | e6c023cb64dea599bb711b2b4ddb197efdb1d187 (diff) | |
download | rockbox-d13f1a485f0e35a6fbbd0a664f14acc3798d52a0.tar.gz rockbox-d13f1a485f0e35a6fbbd0a664f14acc3798d52a0.zip |
Commit FS#8314. This adds strnat[case]cmp written by Martin Pool, which respects numbers within strings, and gives a more intuitive
sorting. This also adds a setting, so that the sorting can be used in the file browser. The implementation is very generic, and can possibly
be used in other places.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@20155 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'firmware')
-rw-r--r-- | firmware/SOURCES | 1 | ||||
-rw-r--r-- | firmware/common/strnatcmp.c | 179 | ||||
-rw-r--r-- | firmware/include/strnatcmp.h | 30 |
3 files changed, 210 insertions, 0 deletions
diff --git a/firmware/SOURCES b/firmware/SOURCES index de42ada0cc..0b6bb155b0 100644 --- a/firmware/SOURCES +++ b/firmware/SOURCES @@ -49,6 +49,7 @@ common/strcasestr.c common/strcat.c common/strchr.c common/strcmp.c +common/strnatcmp.c common/strcpy.c common/strncmp.c common/strncpy.c diff --git a/firmware/common/strnatcmp.c b/firmware/common/strnatcmp.c new file mode 100644 index 0000000000..84e0d38362 --- /dev/null +++ b/firmware/common/strnatcmp.c @@ -0,0 +1,179 @@ +/* -*- mode: c; c-file-style: "k&r" -*- + + strnatcmp.c -- Perform 'natural order' comparisons of strings in C. + Copyright (C) 2000, 2004 by Martin Pool <mbp sourcefrog net> + + 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. +*/ + + +/* partial change history: + * + * 2004-10-10 mbp: Lift out character type dependencies into macros. + * + * Eric Sosman pointed out that ctype functions take a parameter whose + * value must be that of an unsigned int, even on platforms that have + * negative chars in their default char type. + */ + +#include <ctype.h> +#include <string.h> +#include <stdio.h> + +#include "strnatcmp.h" + +#define assert(x) /* nothing */ + + +/* These are defined as macros to make it easier to adapt this code to + * different characters types or comparison functions. */ +static inline int +nat_isdigit(char a) +{ + return isdigit((unsigned char) a); +} + + +static inline int +nat_isspace(char a) +{ + return a == '0' || isspace((unsigned char) a); +} + + +static inline char +nat_toupper(char a) +{ + return toupper((unsigned char) a); +} + + + +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 (!nat_isdigit(*a) && !nat_isdigit(*b)) + return bias; + else if (!nat_isdigit(*a)) + return -1; + else if (!nat_isdigit(*b)) + return +1; + else if (*a < *b) { + if (!bias) + bias = -1; + } else if (*a > *b) { + if (!bias) + bias = +1; + } else if (!*a && !*b) + return bias; + } + + return 0; +} + + +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 (!nat_isdigit(*a) && !nat_isdigit(*b)) + return 0; + else if (!nat_isdigit(*a)) + return -1; + else if (!nat_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; + + assert(a && b); + ai = bi = 0; + while (1) { + ca = a[ai]; cb = b[bi]; + + /* skip over leading spaces or zeros */ + while (nat_isspace(ca)) + ca = a[++ai]; + + while (nat_isspace(cb)) + cb = b[++bi]; + + /* process run of digits */ + if (nat_isdigit(ca) && nat_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 = nat_toupper(ca); + cb = nat_toupper(cb); + } + + if (ca < cb) + return -1; + else if (ca > cb) + return +1; + + ++ai; ++bi; + } +} + + + +int strnatcmp(const char *a, const char *b) { + return strnatcmp0(a, b, 0); +} + + +/* Compare, recognizing numeric string and ignoring case. */ +int strnatcasecmp(const char *a, const char *b) { + return strnatcmp0(a, b, 1); +} diff --git a/firmware/include/strnatcmp.h b/firmware/include/strnatcmp.h new file mode 100644 index 0000000000..50276554e6 --- /dev/null +++ b/firmware/include/strnatcmp.h @@ -0,0 +1,30 @@ +/* -*- mode: c; c-file-style: "k&r" -*- + + strnatcmp.c -- Perform 'natural order' comparisons of strings in C. + Copyright (C) 2000, 2004 by Martin Pool <mbp sourcefrog net> + + 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. +*/ + + +/* CUSTOMIZATION SECTION + * + * You can change this typedef, but must then also change the inline + * functions in strnatcmp.c */ + +int strnatcmp(const char *a, const char *b); +int strnatcasecmp(const char *a, const char *b); |