1 /* Compare strings while treating digits characters numerically.
2 Copyright (C) 1997, 2000, 2002, 2004, 2006, 2009-2010 Free Software
4 This file is part of the GNU C Library.
5 Contributed by Jean-François Bignolles <bignolle@ecoledoc.ibp.fr>, 1997.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License along
18 with this program; if not, write to the Free Software Foundation,
19 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
28 /* states: S_N: normal, S_I: comparing integral part, S_F: comparing
29 fractional parts, S_Z: idem but with leading Zeroes only */
35 /* result_type: CMP: return diff; LEN: compare using len_diff/diff */
40 /* ISDIGIT differs from isdigit, as follows:
41 - Its arg may be any int or unsigned int; it need not be an unsigned char
43 - It's typically faster.
44 POSIX says that only '0' through '9' are digits. Prefer ISDIGIT to
45 isdigit unless it's important to use the locale's definition
46 of `digit' even when the host does not conform to POSIX. */
47 #define ISDIGIT(c) ((unsigned int) (c) - '0' <= 9)
53 # define __strverscmp strverscmp
56 /* Compare S1 and S2 as strings holding indices/version numbers,
57 returning less than, equal to or greater than zero if S1 is less than,
58 equal to or greater than S2 (for more info, see the texinfo doc).
62 __strverscmp (const char *s1, const char *s2)
64 const unsigned char *p1 = (const unsigned char *) s1;
65 const unsigned char *p2 = (const unsigned char *) s2;
70 /* Symbol(s) 0 [1-9] others (padding)
71 Transition (10) 0 (01) d (00) x (11) - */
72 static const unsigned int next_state[] =
75 /* S_N */ S_N, S_I, S_Z, S_N,
76 /* S_I */ S_N, S_I, S_I, S_I,
77 /* S_F */ S_N, S_F, S_F, S_F,
78 /* S_Z */ S_N, S_F, S_Z, S_Z
81 static const int result_type[] =
83 /* state x/x x/d x/0 x/- d/x d/d d/0 d/-
84 0/x 0/d 0/0 0/- -/x -/d -/0 -/- */
86 /* S_N */ CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP,
87 CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
88 /* S_I */ CMP, -1, -1, CMP, 1, LEN, LEN, CMP,
89 1, LEN, LEN, CMP, CMP, CMP, CMP, CMP,
90 /* S_F */ CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP,
91 CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
92 /* S_Z */ CMP, 1, 1, CMP, -1, CMP, CMP, CMP,
101 /* Hint: '0' is a digit too. */
102 state = S_N | ((c1 == '0') + (ISDIGIT (c1) != 0));
104 while ((diff = c1 - c2) == 0 && c1 != '\0')
106 state = next_state[state];
109 state |= (c1 == '0') + (ISDIGIT (c1) != 0);
112 state = result_type[state << 2 | ((c2 == '0') + (ISDIGIT (c2) != 0))];
120 while (ISDIGIT (*p1++))
121 if (!ISDIGIT (*p2++))
124 return ISDIGIT (*p2) ? -1 : diff;
131 weak_alias (__strverscmp, strverscmp)