mpv/misc/natural_sort.c

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/*
* This file is part of mpv.
*
* mpv is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* mpv 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with mpv. If not, see <http://www.gnu.org/licenses/>.
*/
#include "misc/ctype.h"
#include "natural_sort.h"
// Comparison function for an ASCII-only "natural" sort. Case is ignored and
// numbers are ordered by value regardless of padding. Two filenames that differ
// only in the padding of numbers will be considered equal and end up in
// arbitrary order. Bytes outside of A-Z/a-z/0-9 will by sorted by byte value.
int mp_natural_sort_cmp(const char *name1, const char *name2)
{
while (name1[0] && name2[0]) {
if (mp_isdigit(name1[0]) && mp_isdigit(name2[0])) {
while (name1[0] == '0')
name1++;
while (name2[0] == '0')
name2++;
const char *end1 = name1, *end2 = name2;
while (mp_isdigit(*end1))
end1++;
while (mp_isdigit(*end2))
end2++;
// With padding stripped, a number with more digits is bigger.
if ((end1 - name1) < (end2 - name2))
return -1;
if ((end1 - name1) > (end2 - name2))
return 1;
// Same length, lexicographical works.
while (name1 < end1) {
if (name1[0] < name2[0])
return -1;
if (name1[0] > name2[0])
return 1;
name1++;
name2++;
}
} else {
if ((unsigned char)mp_tolower(name1[0]) < (unsigned char)mp_tolower(name2[0]))
return -1;
if ((unsigned char)mp_tolower(name1[0]) > (unsigned char)mp_tolower(name2[0]))
return 1;
name1++;
name2++;
}
}
if (name2[0])
return -1;
if (name1[0])
return 1;
return 0;
}