/* Compare strings while treating digits characters numerically. Copyright (C) 1997-2015 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Jean-Fran�ois Bignolles <bignolle@ecoledoc.ibp.fr>, 1997. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ #include <stdint.h> #include <string.h> #include <ctype.h> /* states: S_N: normal, S_I: comparing integral part, S_F: comparing fractionnal parts, S_Z: idem but with leading Zeroes only */ #define S_N 0x0 #define S_I 0x3 #define S_F 0x6 #define S_Z 0x9 /* result_type: CMP: return diff; LEN: compare using len_diff/diff */ #define CMP 2 #define LEN 3 /* 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; /* Symbol(s) 0 [1-9] others Transition (10) 0 (01) d (00) x */ static const uint8_t next_state[] = { /* state x d 0 */ /* S_N */ S_N, S_I, S_Z, /* S_I */ S_N, S_I, S_I, /* S_F */ S_N, S_F, S_F, /* S_Z */ S_N, S_F, S_Z }; static const int8_t result_type[] = { /* state x/x x/d x/0 d/x d/d d/0 0/x 0/d 0/0 */ /* S_N */ CMP, CMP, CMP, CMP, LEN, CMP, CMP, CMP, CMP, /* S_I */ CMP, -1, -1, +1, LEN, LEN, +1, LEN, LEN, /* S_F */ CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, /* S_Z */ CMP, +1, +1, -1, CMP, CMP, -1, CMP, CMP }; unsigned char c1, c2; int state, diff; 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) { if (c1 == '\0') return diff; state = next_state[state]; c1 = *p1++; c2 = *p2++; state += (c1 == '0') + (isdigit (c1) != 0); } state = result_type[state * 3 + (((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; } } libc_hidden_def(strverscmp)