/* Locale-specific memory comparison. Copyright 1999 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. This program 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 General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* Contributed by Paul Eggert . */ #if HAVE_CONFIG_H # include #endif #ifndef __GNUC__ # ifdef HAVE_ALLOCA_H # include # else # ifdef _AIX # pragma alloca # else # ifdef _WIN32 # include # include # else # ifndef alloca char *alloca (); # endif # endif # endif # endif #endif #if HAVE_STRING_H # include #endif /* Compare S1 (with length S1LEN) and S2 (with length S2LEN) according to the LC_COLLATE locale. S1 and S2 do not overlap, but may be adjacent. Temporarily modify the bytes after S1 and S2, but restore their original contents before returning. */ int memcoll (char *s1, size_t s1len, char *s2, size_t s2len) { int diff; char n1; char n2; /* We will temporarily set the bytes after S1 and S2 to zero, so if S1 and S2 are adjacent, compare to a temporary copy of the earlier, to avoid temporarily stomping on the later. */ if (s1 + s1len == s2) { char *s2copy = alloca (s2len + 1); memcpy (s2copy, s2, s2len); s2 = s2copy; } if (s2 + s2len == s1) { char *s1copy = alloca (s1len + 1); memcpy (s1copy, s1, s1len); s1 = s1copy; } n1 = s1[s1len]; s1[s1len++] = '\0'; n2 = s2[s2len]; s2[s2len++] = '\0'; while (! (diff = strcoll (s1, s2))) { /* strcoll found no difference, but perhaps it was fooled by NUL characters in the data. Work around this problem by advancing past the NUL chars. */ size_t size1 = strlen (s1) + 1; size_t size2 = strlen (s2) + 1; s1 += size1; s2 += size2; s1len -= size1; s2len -= size2; if (s1len == 0) { if (s2len != 0) diff = -1; break; } else if (s2len == 0) { diff = 1; break; } } s1[s1len - 1] = n1; s2[s2len - 1] = n2; return diff; }