1/* exclude.c -- exclude file names
2
3   Copyright (C) 1992, 1993, 1994, 1997, 1999, 2000, 2001, 2002, 2003,
4   2004, 2005, 2006, 2007 Free 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   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
20
21/* Written by Paul Eggert <eggert@twinsun.com>  */
22
23#include <config.h>
24
25#include <stdbool.h>
26
27#include <ctype.h>
28#include <errno.h>
29#include <stddef.h>
30#include <stdio.h>
31#include <stdlib.h>
32#include <string.h>
33
34#include "exclude.h"
35#include "fnmatch.h"
36#include "xalloc.h"
37#include "verify.h"
38
39#if USE_UNLOCKED_IO
40# include "unlocked-io.h"
41#endif
42
43/* Non-GNU systems lack these options, so we don't need to check them.  */
44#ifndef FNM_CASEFOLD
45# define FNM_CASEFOLD 0
46#endif
47#ifndef FNM_EXTMATCH
48# define FNM_EXTMATCH 0
49#endif
50#ifndef FNM_LEADING_DIR
51# define FNM_LEADING_DIR 0
52#endif
53
54verify (((EXCLUDE_ANCHORED | EXCLUDE_INCLUDE | EXCLUDE_WILDCARDS)
55	 & (FNM_PATHNAME | FNM_NOESCAPE | FNM_PERIOD | FNM_LEADING_DIR
56	    | FNM_CASEFOLD | FNM_EXTMATCH))
57	== 0);
58
59/* An exclude pattern-options pair.  The options are fnmatch options
60   ORed with EXCLUDE_* options.  */
61
62struct patopts
63  {
64    char const *pattern;
65    int options;
66  };
67
68/* An exclude list, of pattern-options pairs.  */
69
70struct exclude
71  {
72    struct patopts *exclude;
73    size_t exclude_alloc;
74    size_t exclude_count;
75  };
76
77/* Return a newly allocated and empty exclude list.  */
78
79struct exclude *
80new_exclude (void)
81{
82  return xzalloc (sizeof *new_exclude ());
83}
84
85/* Free the storage associated with an exclude list.  */
86
87void
88free_exclude (struct exclude *ex)
89{
90  free (ex->exclude);
91  free (ex);
92}
93
94/* Return zero if PATTERN matches F, obeying OPTIONS, except that
95   (unlike fnmatch) wildcards are disabled in PATTERN.  */
96
97static int
98fnmatch_no_wildcards (char const *pattern, char const *f, int options)
99{
100  if (! (options & FNM_LEADING_DIR))
101    return ((options & FNM_CASEFOLD)
102	    ? mbscasecmp (pattern, f)
103	    : strcmp (pattern, f));
104  else if (! (options & FNM_CASEFOLD))
105    {
106      size_t patlen = strlen (pattern);
107      int r = strncmp (pattern, f, patlen);
108      if (! r)
109	{
110	  r = f[patlen];
111	  if (r == '/')
112	    r = 0;
113	}
114      return r;
115    }
116  else
117    {
118      /* Walk through a copy of F, seeing whether P matches any prefix
119	 of F.
120
121	 FIXME: This is an O(N**2) algorithm; it should be O(N).
122	 Also, the copy should not be necessary.  However, fixing this
123	 will probably involve a change to the mbs* API.  */
124
125      char *fcopy = xstrdup (f);
126      char *p;
127      int r;
128      for (p = fcopy; ; *p++ = '/')
129	{
130	  p = strchr (p, '/');
131	  if (p)
132	    *p = '\0';
133	  r = mbscasecmp (pattern, fcopy);
134	  if (!p || r <= 0)
135	    break;
136	}
137      free (fcopy);
138      return r;
139    }
140}
141
142bool
143exclude_fnmatch (char const *pattern, char const *f, int options)
144{
145  int (*matcher) (char const *, char const *, int) =
146    (options & EXCLUDE_WILDCARDS
147     ? fnmatch
148     : fnmatch_no_wildcards);
149  bool matched = ((*matcher) (pattern, f, options) == 0);
150  char const *p;
151
152  if (! (options & EXCLUDE_ANCHORED))
153    for (p = f; *p && ! matched; p++)
154      if (*p == '/' && p[1] != '/')
155	matched = ((*matcher) (pattern, p + 1, options) == 0);
156
157  return matched;
158}
159
160/* Return true if EX excludes F.  */
161
162bool
163excluded_file_name (struct exclude const *ex, char const *f)
164{
165  size_t exclude_count = ex->exclude_count;
166
167  /* If no options are given, the default is to include.  */
168  if (exclude_count == 0)
169    return false;
170  else
171    {
172      struct patopts const *exclude = ex->exclude;
173      size_t i;
174
175      /* Otherwise, the default is the opposite of the first option.  */
176      bool excluded = !! (exclude[0].options & EXCLUDE_INCLUDE);
177
178      /* Scan through the options, seeing whether they change F from
179	 excluded to included or vice versa.  */
180      for (i = 0;  i < exclude_count;  i++)
181	{
182	  char const *pattern = exclude[i].pattern;
183	  int options = exclude[i].options;
184	  if (excluded == !! (options & EXCLUDE_INCLUDE))
185	    excluded ^= exclude_fnmatch (pattern, f, options);
186	}
187
188      return excluded;
189    }
190}
191
192/* Append to EX the exclusion PATTERN with OPTIONS.  */
193
194void
195add_exclude (struct exclude *ex, char const *pattern, int options)
196{
197  struct patopts *patopts;
198
199  if (ex->exclude_count == ex->exclude_alloc)
200    ex->exclude = x2nrealloc (ex->exclude, &ex->exclude_alloc,
201			      sizeof *ex->exclude);
202
203  patopts = &ex->exclude[ex->exclude_count++];
204  patopts->pattern = pattern;
205  patopts->options = options;
206}
207
208/* Use ADD_FUNC to append to EX the patterns in FILE_NAME, each with
209   OPTIONS.  LINE_END terminates each pattern in the file.  If
210   LINE_END is a space character, ignore trailing spaces and empty
211   lines in FILE.  Return -1 on failure, 0 on success.  */
212
213int
214add_exclude_file (void (*add_func) (struct exclude *, char const *, int),
215		  struct exclude *ex, char const *file_name, int options,
216		  char line_end)
217{
218  bool use_stdin = file_name[0] == '-' && !file_name[1];
219  FILE *in;
220  char *buf = NULL;
221  char *p;
222  char const *pattern;
223  char const *lim;
224  size_t buf_alloc = 0;
225  size_t buf_count = 0;
226  int c;
227  int e = 0;
228
229  if (use_stdin)
230    in = stdin;
231  else if (! (in = fopen (file_name, "r")))
232    return -1;
233
234  while ((c = getc (in)) != EOF)
235    {
236      if (buf_count == buf_alloc)
237	buf = x2realloc (buf, &buf_alloc);
238      buf[buf_count++] = c;
239    }
240
241  if (ferror (in))
242    e = errno;
243
244  if (!use_stdin && fclose (in) != 0)
245    e = errno;
246
247  buf = xrealloc (buf, buf_count + 1);
248  buf[buf_count] = line_end;
249  lim = buf + buf_count + ! (buf_count == 0 || buf[buf_count - 1] == line_end);
250  pattern = buf;
251
252  for (p = buf; p < lim; p++)
253    if (*p == line_end)
254      {
255	char *pattern_end = p;
256
257	if (isspace ((unsigned char) line_end))
258	  {
259	    for (; ; pattern_end--)
260	      if (pattern_end == pattern)
261		goto next_pattern;
262	      else if (! isspace ((unsigned char) pattern_end[-1]))
263		break;
264	  }
265
266	*pattern_end = '\0';
267	(*add_func) (ex, pattern, options);
268
269      next_pattern:
270	pattern = p + 1;
271      }
272
273  errno = e;
274  return e ? -1 : 0;
275}
276