mirror of
https://github.com/autc04/Retro68.git
synced 2024-09-07 13:54:33 +00:00
93 lines
2.7 KiB
C
93 lines
2.7 KiB
C
/*
|
|
FUNCTION
|
|
<<strverscmp>>---version string compare
|
|
|
|
INDEX
|
|
strverscmp
|
|
|
|
SYNOPSIS
|
|
#define _GNU_SOURCE
|
|
#include <string.h>
|
|
int strverscmp(const char *<[a]>, const char *<[b]>);
|
|
|
|
DESCRIPTION
|
|
<<strverscmp>> compares the string at <[a]> to
|
|
the string at <[b]> in a version-logical order.
|
|
|
|
RETURNS
|
|
|
|
If <<*<[a]>>> version-sorts after <<*<[b]>>>, <<strverscmp>> returns
|
|
a number greater than zero. If the two strings match, <<strverscmp>>
|
|
returns zero. If <<*<[a]>>> version-sorts before <<*<[b]>>>,
|
|
<<strverscmp>> returns a number less than zero.
|
|
|
|
PORTABILITY
|
|
<<strverscmp>> is a GNU extension.
|
|
|
|
<<strverscmp>> requires no supporting OS subroutines. It uses
|
|
isdigit() from elsewhere in this library.
|
|
|
|
QUICKREF
|
|
strverscmp
|
|
*/
|
|
|
|
/*
|
|
From musl src/string/strverscmp.c
|
|
|
|
Copyright © 2005-2014 Rich Felker, et al.
|
|
|
|
Permission is hereby granted, free of charge, to any person obtaining
|
|
a copy of this software and associated documentation files (the
|
|
"Software"), to deal in the Software without restriction, including
|
|
without limitation the rights to use, copy, modify, merge, publish,
|
|
distribute, sublicense, and/or sell copies of the Software, and to
|
|
permit persons to whom the Software is furnished to do so, subject to
|
|
the following conditions:
|
|
|
|
The above copyright notice and this permission notice shall be
|
|
included in all copies or substantial portions of the Software.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
|
|
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
|
|
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
|
|
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
|
|
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
*/
|
|
|
|
#define _GNU_SOURCE
|
|
#include <ctype.h>
|
|
#include <string.h>
|
|
|
|
int strverscmp(const char *l0, const char *r0)
|
|
{
|
|
const unsigned char *l = (const void *)l0;
|
|
const unsigned char *r = (const void *)r0;
|
|
size_t i, dp, j;
|
|
int z = 1;
|
|
|
|
/* Find maximal matching prefix and track its maximal digit
|
|
* suffix and whether those digits are all zeros. */
|
|
for (dp=i=0; l[i]==r[i]; i++) {
|
|
int c = l[i];
|
|
if (!c) return 0;
|
|
if (!isdigit(c)) dp=i+1, z=1;
|
|
else if (c!='0') z=0;
|
|
}
|
|
|
|
if (l[dp]!='0' && r[dp]!='0') {
|
|
/* If we're not looking at a digit sequence that began
|
|
* with a zero, longest digit string is greater. */
|
|
for (j=i; isdigit(l[j]); j++)
|
|
if (!isdigit(r[j])) return 1;
|
|
if (isdigit(r[j])) return -1;
|
|
} else if (z && dp<i && (isdigit(l[i]) || isdigit(r[i]))) {
|
|
/* Otherwise, if common prefix of digit sequence is
|
|
* all zeros, digits order less than non-digits. */
|
|
return (unsigned char)(l[i]-'0') - (unsigned char)(r[i]-'0');
|
|
}
|
|
|
|
return l[i] - r[i];
|
|
}
|