| 1 | /* Compare strings while treating digits characters numerically.
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| 2 | Copyright (C) 1997, 2000, 2002 Free Software Foundation, Inc.
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| 3 | This file is part of the GNU C Library.
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| 4 | Contributed by Jean-François Bignolles <[email protected]>, 1997.
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| 5 |
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| 6 | The GNU C Library is free software; you can redistribute it and/or
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| 7 | modify it under the terms of the GNU Library General Public License as
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| 8 | published by the Free Software Foundation; either version 2 of the
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| 9 | License, or (at your option) any later version.
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| 10 |
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| 11 | The GNU C Library is distributed in the hope that it will be useful,
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| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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| 14 | Library General Public License for more details.
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| 15 |
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| 16 | You should have received a copy of the GNU Library General Public
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| 17 | License along with the GNU C Library; see the file COPYING.LIB. If not,
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| 18 | write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
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| 19 | Boston, MA 02110-1301, USA. */
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| 20 |
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| 21 | #if HAVE_CONFIG_H
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| 22 | # include <config.h>
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| 23 | #endif
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| 24 |
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| 25 | #include <string.h>
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| 26 | #include <ctype.h>
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| 27 |
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| 28 | /* states: S_N: normal, S_I: comparing integral part, S_F: comparing
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| 29 | fractional parts, S_Z: idem but with leading Zeroes only */
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| 30 | #define S_N 0x0
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| 31 | #define S_I 0x4
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| 32 | #define S_F 0x8
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| 33 | #define S_Z 0xC
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| 34 |
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| 35 | /* result_type: CMP: return diff; LEN: compare using len_diff/diff */
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| 36 | #define CMP 2
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| 37 | #define LEN 3
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| 38 |
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| 39 |
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| 40 | /* ISDIGIT differs from isdigit, as follows:
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| 41 | - Its arg may be any int or unsigned int; it need not be an unsigned char.
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| 42 | - It's guaranteed to evaluate its argument exactly once.
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| 43 | - It's typically faster.
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| 44 | POSIX says that only '0' through '9' are digits. Prefer ISDIGIT to
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| 45 | ISDIGIT_LOCALE unless it's important to use the locale's definition
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| 46 | of `digit' even when the host does not conform to POSIX. */
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| 47 | #define ISDIGIT(c) ((unsigned) (c) - '0' <= 9)
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| 48 |
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| 49 | #undef __strverscmp
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| 50 | #undef strverscmp
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| 51 |
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| 52 | #ifndef weak_alias
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| 53 | # define __strverscmp strverscmp
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| 54 | #endif
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| 55 |
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| 56 | /* Compare S1 and S2 as strings holding indices/version numbers,
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| 57 | returning less than, equal to or greater than zero if S1 is less than,
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| 58 | equal to or greater than S2 (for more info, see the texinfo doc).
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| 59 | */
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| 60 |
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| 61 | int
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| 62 | __strverscmp (const char *s1, const char *s2)
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| 63 | {
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| 64 | const unsigned char *p1 = (const unsigned char *) s1;
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| 65 | const unsigned char *p2 = (const unsigned char *) s2;
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| 66 | unsigned char c1, c2;
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| 67 | int state;
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| 68 | int diff;
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| 69 |
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| 70 | /* Symbol(s) 0 [1-9] others (padding)
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| 71 | Transition (10) 0 (01) d (00) x (11) - */
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| 72 | static const unsigned int next_state[] =
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| 73 | {
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| 74 | /* state x d 0 - */
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| 75 | /* S_N */ S_N, S_I, S_Z, S_N,
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| 76 | /* S_I */ S_N, S_I, S_I, S_I,
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| 77 | /* S_F */ S_N, S_F, S_F, S_F,
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| 78 | /* S_Z */ S_N, S_F, S_Z, S_Z
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| 79 | };
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| 80 |
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| 81 | static const int result_type[] =
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| 82 | {
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| 83 | /* state x/x x/d x/0 x/- d/x d/d d/0 d/-
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| 84 | 0/x 0/d 0/0 0/- -/x -/d -/0 -/- */
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| 85 |
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| 86 | /* S_N */ CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP,
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| 87 | CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
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| 88 | /* S_I */ CMP, -1, -1, CMP, 1, LEN, LEN, CMP,
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| 89 | 1, LEN, LEN, CMP, CMP, CMP, CMP, CMP,
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| 90 | /* S_F */ CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP,
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| 91 | CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
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| 92 | /* S_Z */ CMP, 1, 1, CMP, -1, CMP, CMP, CMP,
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| 93 | -1, CMP, CMP, CMP
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| 94 | };
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| 95 |
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| 96 | if (p1 == p2)
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| 97 | return 0;
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| 98 |
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| 99 | c1 = *p1++;
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| 100 | c2 = *p2++;
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| 101 | /* Hint: '0' is a digit too. */
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| 102 | state = S_N | ((c1 == '0') + (ISDIGIT (c1) != 0));
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| 103 |
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| 104 | while ((diff = c1 - c2) == 0 && c1 != '\0')
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| 105 | {
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| 106 | state = next_state[state];
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| 107 | c1 = *p1++;
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| 108 | c2 = *p2++;
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| 109 | state |= (c1 == '0') + (ISDIGIT (c1) != 0);
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| 110 | }
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| 111 |
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| 112 | state = result_type[state << 2 | ((c2 == '0') + (ISDIGIT (c2) != 0))];
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| 113 |
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| 114 | switch (state)
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| 115 | {
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| 116 | case CMP:
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| 117 | return diff;
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| 118 |
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| 119 | case LEN:
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| 120 | while (ISDIGIT (*p1++))
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| 121 | if (!ISDIGIT (*p2++))
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| 122 | return 1;
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| 123 |
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| 124 | return ISDIGIT (*p2) ? -1 : diff;
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| 125 |
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| 126 | default:
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| 127 | return state;
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| 128 | }
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| 129 | }
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| 130 | #ifdef weak_alias
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| 131 | weak_alias (__strverscmp, strverscmp)
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| 132 | #endif
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