1/* Compare strings while treating digits characters numerically.
2 Copyright (C) 1997-2020 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 <https://www.gnu.org/licenses/>. */
19
20#include <stdint.h>
21#include <string.h>
22#include <ctype.h>
23
24/* states: S_N: normal, S_I: comparing integral part, S_F: comparing
25 fractionnal parts, S_Z: idem but with leading Zeroes only */
26#define S_N 0x0
27#define S_I 0x3
28#define S_F 0x6
29#define S_Z 0x9
30
31/* result_type: CMP: return diff; LEN: compare using len_diff/diff */
32#define CMP 2
33#define LEN 3
34
35
36/* Compare S1 and S2 as strings holding indices/version numbers,
37 returning less than, equal to or greater than zero if S1 is less than,
38 equal to or greater than S2 (for more info, see the texinfo doc).
39*/
40
41int
42__strverscmp (const char *s1, const char *s2)
43{
44 const unsigned char *p1 = (const unsigned char *) s1;
45 const unsigned char *p2 = (const unsigned char *) s2;
46
47 /* Symbol(s) 0 [1-9] others
48 Transition (10) 0 (01) d (00) x */
49 static const uint8_t next_state[] =
50 {
51 /* state x d 0 */
52 /* S_N */ S_N, S_I, S_Z,
53 /* S_I */ S_N, S_I, S_I,
54 /* S_F */ S_N, S_F, S_F,
55 /* S_Z */ S_N, S_F, S_Z
56 };
57
58 static const int8_t result_type[] =
59 {
60 /* state x/x x/d x/0 d/x d/d d/0 0/x 0/d 0/0 */
61
62 /* S_N */ CMP, CMP, CMP, CMP, LEN, CMP, CMP, CMP, CMP,
63 /* S_I */ CMP, -1, -1, +1, LEN, LEN, +1, LEN, LEN,
64 /* S_F */ CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
65 /* S_Z */ CMP, +1, +1, -1, CMP, CMP, -1, CMP, CMP
66 };
67
68 if (p1 == p2)
69 return 0;
70
71 unsigned char c1 = *p1++;
72 unsigned char c2 = *p2++;
73 /* Hint: '0' is a digit too. */
74 int state = S_N + ((c1 == '0') + (isdigit (c1) != 0));
75
76 int diff;
77 while ((diff = c1 - c2) == 0)
78 {
79 if (c1 == '\0')
80 return diff;
81
82 state = next_state[state];
83 c1 = *p1++;
84 c2 = *p2++;
85 state += (c1 == '0') + (isdigit (c1) != 0);
86 }
87
88 state = result_type[state * 3 + (((c2 == '0') + (isdigit (c2) != 0)))];
89
90 switch (state)
91 {
92 case CMP:
93 return diff;
94
95 case LEN:
96 while (isdigit (*p1++))
97 if (!isdigit (*p2++))
98 return 1;
99
100 return isdigit (*p2) ? -1 : diff;
101
102 default:
103 return state;
104 }
105}
106libc_hidden_def (__strverscmp)
107weak_alias (__strverscmp, strverscmp)
108