1 /* Compare strings while treating digits characters numerically.
2 Copyright (C) 1997-2015 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.
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.
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.
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/>. */
24 /* states: S_N: normal, S_I: comparing integral part, S_F: comparing
25 fractionnal parts, S_Z: idem but with leading Zeroes only */
31 /* result_type: CMP: return diff; LEN: compare using len_diff/diff */
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).
46 const unsigned char *p1 = (const unsigned char *) s1;
47 const unsigned char *p2 = (const unsigned char *) s2;
49 /* Symbol(s) 0 [1-9] others
50 Transition (10) 0 (01) d (00) x */
51 static const uint8_t next_state[] =
54 /* S_N */ S_N, S_I, S_Z,
55 /* S_I */ S_N, S_I, S_I,
56 /* S_F */ S_N, S_F, S_F,
57 /* S_Z */ S_N, S_F, S_Z
60 static const int8_t result_type[] =
62 /* state x/x x/d x/0 d/x d/d d/0 0/x 0/d 0/0 */
64 /* S_N */ CMP, CMP, CMP, CMP, LEN, CMP, CMP, CMP, CMP,
65 /* S_I */ CMP, -1, -1, +1, LEN, LEN, +1, LEN, LEN,
66 /* S_F */ CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
67 /* S_Z */ CMP, +1, +1, -1, CMP, CMP, -1, CMP, CMP
73 unsigned char c1 = *p1++;
74 unsigned char c2 = *p2++;
75 /* Hint: '0' is a digit too. */
76 int state = S_N + ((c1 == '0') + (isdigit (c1) != 0));
79 while ((diff = c1 - c2) == 0)
84 state = next_state[state];
87 state += (c1 == '0') + (isdigit (c1) != 0);
90 state = result_type[state * 3 + (((c2 == '0') + (isdigit (c2) != 0)))];
98 while (isdigit (*p1++))
102 return isdigit (*p2) ? -1 : diff;
108 libc_hidden_def (__strverscmp)
109 weak_alias (__strverscmp, strverscmp)