105 lines
3 KiB
C
105 lines
3 KiB
C
/* Compare strings while treating digits characters numerically.
|
|
2 Copyright (C) 1997-2016 Free Software Foundation, Inc.
|
|
3 This file is part of the GNU C Library.
|
|
4 Contributed by Jean-François Bignolles <bignolle@ecoledoc.ibp.fr>, 1997.
|
|
5
|
|
6 The GNU C Library is free software; you can redistribute it and/or
|
|
7 modify it under the terms of the GNU Lesser General Public
|
|
8 License as published by the Free Software Foundation; either
|
|
9 version 2.1 of the License, or (at your option) any later version.
|
|
10
|
|
11 The GNU C Library is distributed in the hope that it will be useful,
|
|
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
14 Lesser General Public License for more details.
|
|
15
|
|
16 You should have received a copy of the GNU Lesser General Public
|
|
17 License along with the GNU C Library; if not, see
|
|
18 <http://www.gnu.org/licenses/>. */
|
|
|
|
#include "strverscmp.h"
|
|
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
#include <ctype.h>
|
|
|
|
/* states: S_N: normal, S_I: comparing integral part, S_F: comparing
|
|
fractionnal parts, S_Z: idem but with leading Zeroes only */
|
|
#define S_N 0x0
|
|
#define S_I 0x3
|
|
#define S_F 0x6
|
|
#define S_Z 0x9
|
|
|
|
/* result_type: CMP: return diff; LEN: compare using len_diff/diff */
|
|
#define CMP 2
|
|
#define LEN 3
|
|
|
|
/* Compare S1 and S2 as strings holding indices/version numbers,
|
|
returning less than, equal to or greater than zero if S1 is less than,
|
|
equal to or greater than S2 (for more info, see the texinfo doc).
|
|
*/
|
|
|
|
int strverscmp (const char *s1, const char *s2)
|
|
{
|
|
const unsigned char *p1 = (const unsigned char *) s1;
|
|
const unsigned char *p2 = (const unsigned char *) s2;
|
|
|
|
/* Symbol(s) 0 [1-9] others
|
|
Transition (10) 0 (01) d (00) x */
|
|
static const uint8_t next_state[] =
|
|
{
|
|
/* state x d 0 */
|
|
/* S_N */ S_N, S_I, S_Z,
|
|
/* S_I */ S_N, S_I, S_I,
|
|
/* S_F */ S_N, S_F, S_F,
|
|
/* S_Z */ S_N, S_F, S_Z
|
|
};
|
|
|
|
static const int8_t result_type[] =
|
|
{
|
|
/* state x/x x/d x/0 d/x d/d d/0 0/x 0/d 0/0 */
|
|
|
|
/* S_N */ CMP, CMP, CMP, CMP, LEN, CMP, CMP, CMP, CMP,
|
|
/* S_I */ CMP, -1, -1, +1, LEN, LEN, +1, LEN, LEN,
|
|
/* S_F */ CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
|
|
/* S_Z */ CMP, +1, +1, -1, CMP, CMP, -1, CMP, CMP
|
|
};
|
|
|
|
if (p1 == p2)
|
|
return 0;
|
|
|
|
unsigned char c1 = *p1++;
|
|
unsigned char c2 = *p2++;
|
|
/* Hint: '0' is a digit too. */
|
|
int state = S_N + ((c1 == '0') + (isdigit (c1) != 0));
|
|
|
|
int diff;
|
|
while ((diff = c1 - c2) == 0)
|
|
{
|
|
if (c1 == '\0')
|
|
return diff;
|
|
|
|
state = next_state[state];
|
|
c1 = *p1++;
|
|
c2 = *p2++;
|
|
state += (c1 == '0') + (isdigit (c1) != 0);
|
|
}
|
|
|
|
state = result_type[state * 3 + (((c2 == '0') + (isdigit (c2) != 0)))];
|
|
|
|
switch (state)
|
|
{
|
|
case CMP:
|
|
return diff;
|
|
|
|
case LEN:
|
|
while (isdigit (*p1++))
|
|
if (!isdigit (*p2++))
|
|
return 1;
|
|
|
|
return isdigit (*p2) ? -1 : diff;
|
|
|
|
default:
|
|
return state;
|
|
}
|
|
}
|