Dogcows Code - chaz/tar/blob - lib/exclude.c

   1 /* exclude.c -- exclude file names
   2
   3    Copyright (C) 1992, 1993, 1994, 1997, 1999, 2000, 2001, 2002, 2003 Free
   4    Software Foundation, Inc.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; see the file COPYING.
  18    If not, write to the Free Software Foundation,
  19    59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  20
  21 /* Written by Paul Eggert <eggert@twinsun.com>  */
  22
  23 #if HAVE_CONFIG_H
  24 # include <config.h>
  25 #endif
  26
  27 #include <stdbool.h>
  28
  29 #include <errno.h>
  30 #ifndef errno
  31 extern int errno;
  32 #endif
  33 #include <stddef.h>
  34 #include <stdio.h>
  35 #if HAVE_STDLIB_H
  36 # include <stdlib.h>
  37 #endif
  38 #if HAVE_STRING_H
  39 # include <string.h>
  40 #endif
  41 #if HAVE_STRINGS_H
  42 # include <strings.h>
  43 #endif
  44 #if HAVE_INTTYPES_H
  45 # include <inttypes.h>
  46 #else
  47 # if HAVE_STDINT_H
  48 #  include <stdint.h>
  49 # endif
  50 #endif
  51
  52 #include "exclude.h"
  53 #include "fnmatch.h"
  54 #include "unlocked-io.h"
  55 #include "xalloc.h"
  56
  57 #ifndef SIZE_MAX
  58 # define SIZE_MAX ((size_t) -1)
  59 #endif
  60
  61 /* Verify a requirement at compile-time (unlike assert, which is runtime).  */
  62 #define verify(name, assertion) struct name { char a[(assertion) ? 1 : -1]; }
  63
  64 /* Non-GNU systems lack these options, so we don't need to check them.  */
  65 #ifndef FNM_CASEFOLD
  66 # define FNM_CASEFOLD 0
  67 #endif
  68 #ifndef FNM_LEADING_DIR
  69 # define FNM_LEADING_DIR 0
  70 #endif
  71
  72 verify (EXCLUDE_macros_do_not_collide_with_FNM_macros,
  73         (((EXCLUDE_ANCHORED | EXCLUDE_INCLUDE | EXCLUDE_WILDCARDS)
  74           & (FNM_PATHNAME | FNM_NOESCAPE | FNM_PERIOD | FNM_LEADING_DIR
  75              | FNM_CASEFOLD))
  76          == 0));
  77
  78 /* An exclude pattern-options pair.  The options are fnmatch options
  79    ORed with EXCLUDE_* options.  */
  80
  81 struct patopts
  82   {
  83     char const *pattern;
  84     int options;
  85   };
  86
  87 /* An exclude list, of pattern-options pairs.  */
  88
  89 struct exclude
  90   {
  91     struct patopts *exclude;
  92     size_t exclude_alloc;
  93     size_t exclude_count;
  94   };
  95
  96 /* Return a newly allocated and empty exclude list.  */
  97
  98 struct exclude *
  99 new_exclude (void)
 100 {
 101   struct exclude *ex = xmalloc (sizeof *ex);
 102   ex->exclude_count = 0;
 103   ex->exclude_alloc = (1 << 6); /* This must be a power of 2.  */
 104   ex->exclude = xmalloc (ex->exclude_alloc * sizeof ex->exclude[0]);
 105   return ex;
 106 }
 107
 108 /* Free the storage associated with an exclude list.  */
 109
 110 void
 111 free_exclude (struct exclude *ex)
 112 {
 113   free (ex->exclude);
 114   free (ex);
 115 }
 116
 117 /* Return zero if PATTERN matches F, obeying OPTIONS, except that
 118    (unlike fnmatch) wildcards are disabled in PATTERN.  */
 119
 120 static int
 121 fnmatch_no_wildcards (char const *pattern, char const *f, int options)
 122 {
 123   if (! (options & FNM_LEADING_DIR))
 124     return ((options & FNM_CASEFOLD)
 125             ? strcasecmp (pattern, f)
 126             : strcmp (pattern, f));
 127   else
 128     {
 129       size_t patlen = strlen (pattern);
 130       int r = ((options & FNM_CASEFOLD)
 131                 ? strncasecmp (pattern, f, patlen)
 132                 : strncmp (pattern, f, patlen));
 133       if (! r)
 134         {
 135           r = f[patlen];
 136           if (r == '/')
 137             r = 0;
 138         }
 139       return r;
 140     }
 141 }
 142
 143 /* Return true if EX excludes F.  */
 144
 145 bool
 146 excluded_filename (struct exclude const *ex, char const *f)
 147 {
 148   size_t exclude_count = ex->exclude_count;
 149
 150   /* If no options are given, the default is to include.  */
 151   if (exclude_count == 0)
 152     return false;
 153   else
 154     {
 155       struct patopts const *exclude = ex->exclude;
 156       size_t i;
 157
 158       /* Otherwise, the default is the opposite of the first option.  */
 159       bool excluded = !! (exclude[0].options & EXCLUDE_INCLUDE);
 160
 161       /* Scan through the options, seeing whether they change F from
 162          excluded to included or vice versa.  */
 163       for (i = 0;  i < exclude_count;  i++)
 164         {
 165           char const *pattern = exclude[i].pattern;
 166           int options = exclude[i].options;
 167           if (excluded == !! (options & EXCLUDE_INCLUDE))
 168             {
 169               int (*matcher) (char const *, char const *, int) =
 170                 (options & EXCLUDE_WILDCARDS
 171                  ? fnmatch
 172                  : fnmatch_no_wildcards);
 173               bool matched = ((*matcher) (pattern, f, options) == 0);
 174               char const *p;
 175
 176               if (! (options & EXCLUDE_ANCHORED))
 177                 for (p = f; *p && ! matched; p++)
 178                   if (*p == '/' && p[1] != '/')
 179                     matched = ((*matcher) (pattern, p + 1, options) == 0);
 180
 181               excluded ^= matched;
 182             }
 183         }
 184
 185       return excluded;
 186     }
 187 }
 188
 189 /* Append to EX the exclusion PATTERN with OPTIONS.  */
 190
 191 void
 192 add_exclude (struct exclude *ex, char const *pattern, int options)
 193 {
 194   struct patopts *patopts;
 195
 196   if (ex->exclude_alloc <= ex->exclude_count)
 197     {
 198       size_t s = 2 * ex->exclude_alloc;
 199       if (! (0 < s && s <= SIZE_MAX / sizeof ex->exclude[0]))
 200         xalloc_die ();
 201       ex->exclude_alloc = s;
 202       ex->exclude = xrealloc (ex->exclude, s * sizeof ex->exclude[0]);
 203     }
 204
 205   patopts = &ex->exclude[ex->exclude_count++];
 206   patopts->pattern = pattern;
 207   patopts->options = options;
 208 }
 209
 210 /* Use ADD_FUNC to append to EX the patterns in FILENAME, each with
 211    OPTIONS.  LINE_END terminates each pattern in the file.  Return -1
 212    on failure, 0 on success.  */
 213
 214 int
 215 add_exclude_file (void (*add_func) (struct exclude *, char const *, int),
 216                   struct exclude *ex, char const *filename, int options,
 217                   char line_end)
 218 {
 219   bool use_stdin = filename[0] == '-' && !filename[1];
 220   FILE *in;
 221   char *buf;
 222   char *p;
 223   char const *pattern;
 224   char const *lim;
 225   size_t buf_alloc = (1 << 10);  /* This must be a power of two.  */
 226   size_t buf_count = 0;
 227   int c;
 228   int e = 0;
 229
 230   if (use_stdin)
 231     in = stdin;
 232   else if (! (in = fopen (filename, "r")))
 233     return -1;
 234
 235   buf = xmalloc (buf_alloc);
 236
 237   while ((c = getc (in)) != EOF)
 238     {
 239       buf[buf_count++] = c;
 240       if (buf_count == buf_alloc)
 241         {
 242           buf_alloc *= 2;
 243           if (! buf_alloc)
 244             xalloc_die ();
 245           buf = xrealloc (buf, buf_alloc);
 246         }
 247     }
 248
 249   if (ferror (in))
 250     e = errno;
 251
 252   if (!use_stdin && fclose (in) != 0)
 253     e = errno;
 254
 255   buf = xrealloc (buf, buf_count + 1);
 256
 257   for (pattern = p = buf, lim = buf + buf_count;  p <= lim;  p++)
 258     if (p < lim ? *p == line_end : buf < p && p[-1])
 259       {
 260         *p = '\0';
 261         (*add_func) (ex, pattern, options);
 262         pattern = p + 1;
 263       }
 264
 265   errno = e;
 266   return e ? -1 : 0;
 267 }