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author | Jim Meyering <jim@meyering.net> | 1999-07-04 10:38:37 +0000 |
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committer | Jim Meyering <jim@meyering.net> | 1999-07-04 10:38:37 +0000 |
commit | 08da7047d0c61ed1e67d96edcc1e83501c241d3d (patch) | |
tree | f552256f3dac6da29b7dd617f5ba702cf8ead1e0 /lib/memcoll.c | |
parent | 0aa86039dd5e591bdbbbe2eaad770c89bf9e25fa (diff) | |
download | coreutils-08da7047d0c61ed1e67d96edcc1e83501c241d3d.tar.xz |
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Diffstat (limited to 'lib/memcoll.c')
-rw-r--r-- | lib/memcoll.c | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/lib/memcoll.c b/lib/memcoll.c new file mode 100644 index 000000000..11a61ad60 --- /dev/null +++ b/lib/memcoll.c @@ -0,0 +1,108 @@ +/* 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 <eggert@twinsun.com>. */ + +#if HAVE_CONFIG_H +# include <config.h> +#endif + +#ifndef __GNUC__ +# ifdef HAVE_ALLOCA_H +# include <alloca.h> +# else +# ifdef _AIX + # pragma alloca +# else +# ifdef _WIN32 +# include <malloc.h> +# include <io.h> +# else +# ifndef alloca +char *alloca (); +# endif +# endif +# endif +# endif +#endif + +#if HAVE_STRING_H +# include <string.h> +#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; +} |