contrib/tar/lib/exclude.c

   1 /* exclude.c -- exclude file names
   2
   3    Copyright 1992, 1993, 1994, 1997, 1999, 2000, 2001 Free Software
   4    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 #if HAVE_STDBOOL_H
  28 # include <stdbool.h>
  29 #else
  30 typedef enum {false = 0, true = 1} bool;
  31 #endif
  32
  33 #include <errno.h>
  34 #ifndef errno
  35 extern int errno;
  36 #endif
  37 #include <stdio.h>
  38 #if HAVE_SYS_TYPES_H
  39 # include <sys/types.h>
  40 #endif
  41 #if HAVE_STDLIB_H
  42 # include <stdlib.h>
  43 #endif
  44 #if HAVE_STRING_H
  45 # include <string.h>
  46 #endif
  47 #if HAVE_STRINGS_H
  48 # include <strings.h>
  49 #endif
  50 #if HAVE_INTTYPES_H
  51 # include <inttypes.h>
  52 #else
  53 # if HAVE_STDINT_H
  54 #  include <stdint.h>
  55 # endif
  56 #endif
  57
  58 #include "exclude.h"
  59 #include "fnmatch.h"
  60 #include "xalloc.h"
  61
  62 #ifndef SIZE_MAX
  63 # define SIZE_MAX ((size_t) -1)
  64 #endif
  65
  66 /* Verify a requirement at compile-time (unlike assert, which is runtime).  */
  67 #define verify(name, assertion) struct name { char a[(assertion) ? 1 : -1]; }
  68
  69 verify (EXCLUDE_macros_do_not_collide_with_FNM_macros,
  70         (((EXCLUDE_ANCHORED | EXCLUDE_INCLUDE | EXCLUDE_WILDCARDS)
  71           & (FNM_FILE_NAME | FNM_NOESCAPE | FNM_PERIOD | FNM_LEADING_DIR
  72              | FNM_CASEFOLD))
  73          == 0));
  74
  75 /* An exclude pattern-options pair.  The options are fnmatch options
  76    ORed with EXCLUDE_* options.  */
  77
  78 struct patopts
  79   {
  80     char const *pattern;
  81     int options;
  82   };
  83
  84 /* An exclude list, of pattern-options pairs.  */
  85
  86 struct exclude
  87   {
  88     struct patopts *exclude;
  89     size_t exclude_alloc;
  90     size_t exclude_count;
  91   };
  92
  93 /* Return a newly allocated and empty exclude list.  */
  94
  95 struct exclude *
  96 new_exclude (void)
  97 {
  98   struct exclude *ex = (struct exclude *) xmalloc (sizeof *ex);
  99   ex->exclude_count = 0;
 100   ex->exclude_alloc = (1 << 6); /* This must be a power of 2.  */
 101   ex->exclude = (struct patopts *) xmalloc (ex->exclude_alloc
 102                                             * sizeof ex->exclude[0]);
 103   return ex;
 104 }
 105
 106 /* Free the storage associated with an exclude list.  */
 107
 108 void
 109 free_exclude (struct exclude *ex)
 110 {
 111   free (ex->exclude);
 112   free (ex);
 113 }
 114
 115 /* Return zero if PATTERN matches F, obeying OPTIONS, except that
 116    (unlike fnmatch) wildcards are disabled in PATTERN.  */
 117
 118 static int
 119 fnmatch_no_wildcards (char const *pattern, char const *f, int options)
 120 {
 121   if (! (options & FNM_LEADING_DIR))
 122     return ((options & FNM_CASEFOLD)
 123             ? strcasecmp (pattern, f)
 124             : strcmp (pattern, f));
 125   else
 126     {
 127       size_t patlen = strlen (pattern);
 128       int r = ((options & FNM_CASEFOLD)
 129                 ? strncasecmp (pattern, f, patlen)
 130                 : strncmp (pattern, f, patlen));
 131       if (! r)
 132         {
 133           r = f[patlen];
 134           if (r == '/')
 135             r = 0;
 136         }
 137       return r;
 138     }
 139 }
 140
 141 /* Return true if EX excludes F.  */
 142
 143 bool
 144 excluded_filename (struct exclude const *ex, char const *f)
 145 {
 146   size_t exclude_count = ex->exclude_count;
 147
 148   /* If no options are given, the default is to include.  */
 149   if (exclude_count == 0)
 150     return 0;
 151   else
 152     {
 153       struct patopts const *exclude = ex->exclude;
 154       size_t i;
 155
 156       /* Otherwise, the default is the opposite of the first option.  */
 157       bool excluded = !! (exclude[0].options & EXCLUDE_INCLUDE);
 158
 159       /* Scan through the options, seeing whether they change F from
 160          excluded to included or vice versa.  */
 161       for (i = 0;  i < exclude_count;  i++)
 162         {
 163           char const *pattern = exclude[i].pattern;
 164           int options = exclude[i].options;
 165           if (excluded == !! (options & EXCLUDE_INCLUDE))
 166             {
 167               int (*matcher) PARAMS ((char const *, char const *, int)) =
 168                 (options & EXCLUDE_WILDCARDS
 169                  ? fnmatch
 170                  : fnmatch_no_wildcards);
 171               bool matched = ((*matcher) (pattern, f, options) == 0);
 172               char const *p;
 173
 174               if (! (options & EXCLUDE_ANCHORED))
 175                 for (p = f; *p && ! matched; p++)
 176                   if (*p == '/' && p[1] != '/')
 177                     matched = ((*matcher) (pattern, p + 1, options) == 0);
 178
 179               excluded ^= matched;
 180             }
 181         }
 182
 183       return excluded;
 184     }
 185 }
 186
 187 /* Append to EX the exclusion PATTERN with OPTIONS.  */
 188
 189 void
 190 add_exclude (struct exclude *ex, char const *pattern, int options)
 191 {
 192   struct patopts *patopts;
 193
 194   if (ex->exclude_alloc <= ex->exclude_count)
 195     {
 196       size_t s = 2 * ex->exclude_alloc;
 197       if (! (0 < s && s <= SIZE_MAX / sizeof ex->exclude[0]))
 198         xalloc_die ();
 199       ex->exclude_alloc = s;
 200       ex->exclude = (struct patopts *) xrealloc (ex->exclude,
 201                                                  s * sizeof ex->exclude[0]);
 202     }
 203
 204   patopts = &ex->exclude[ex->exclude_count++];
 205   patopts->pattern = pattern;
 206   patopts->options = options;
 207 }
 208
 209 /* Use ADD_FUNC to append to EX the patterns in FILENAME, each with
 210    OPTIONS.  LINE_END terminates each pattern in the file.  Return -1
 211    on failure, 0 on success.  */
 212
 213 int
 214 add_exclude_file (void (*add_func) PARAMS ((struct exclude *,
 215                                             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 }