/* Compare strings while treating digits characters numerically. Copyright (C) 1997, 2000 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Jean-Francois Bignolles , 1997. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #if HAVE_CONFIG_H # include #endif #include #include /* states: S_N: normal, S_I: comparing integral part, S_F: comparing Fractional parts, S_Z: idem but with leading Zeroes only */ #define S_N 0x0 #define S_I 0x4 #define S_F 0x8 #define S_Z 0xC /* result_type: CMP: return diff; LEN: compare using len_diff/diff */ #define CMP 2 #define LEN 3 /* ISDIGIT differs from isdigit, as follows: - Its arg may be any int or unsigned int; it need not be an unsigned char. - It's guaranteed to evaluate its argument exactly once. - It's typically faster. Posix 1003.2-1992 section 2.5.2.1 page 50 lines 1556-1558 says that only '0' through '9' are digits. Prefer ISDIGIT to isdigit unless it's important to use the locale's definition of `digit' even when the host does not conform to Posix. */ #define ISDIGIT(c) ((unsigned) (c) - '0' <= 9) /* 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; unsigned char c1, c2; int state; int diff; /* Symbol(s) 0 [1-9] others (padding) Transition (10) 0 (01) d (00) x (11) - */ static const unsigned int next_state[] = { /* state x d 0 - */ /* S_N */ S_N, S_I, S_Z, S_N, /* S_I */ S_N, S_I, S_I, S_I, /* S_F */ S_N, S_F, S_F, S_F, /* S_Z */ S_N, S_F, S_Z, S_Z }; static const int result_type[] = { /* state x/x x/d x/0 x/- d/x d/d d/0 d/- 0/x 0/d 0/0 0/- -/x -/d -/0 -/- */ /* S_N */ CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, /* S_I */ CMP, -1, -1, CMP, 1, LEN, LEN, CMP, 1, LEN, LEN, CMP, CMP, CMP, CMP, CMP, /* S_F */ CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, /* S_Z */ CMP, 1, 1, CMP, -1, CMP, CMP, CMP, -1, CMP, CMP, CMP }; if (p1 == p2) return 0; c1 = *p1++; c2 = *p2++; /* Hint: '0' is a digit too. */ state = S_N | ((c1 == '0') + (ISDIGIT (c1) != 0)); while ((diff = c1 - c2) == 0 && c1 != '\0') { state = next_state[state]; c1 = *p1++; c2 = *p2++; state |= (c1 == '0') + (ISDIGIT (c1) != 0); } state = result_type[state << 2 | ((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; } }