1 /* $NetBSD: dir.c,v 1.1.1.1 2016/01/13 03:15:30 christos Exp $ */
2
3 /* Read, sort and compare two directories. Used for GNU DIFF.
4
5 Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1998, 2001, 2002
6 Free Software Foundation, Inc.
7
8 This file is part of GNU DIFF.
9
10 GNU DIFF is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 2, or (at your option)
13 any later version.
14
15 GNU DIFF is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
19
20 You should have received a copy of the GNU General Public License
21 along with this program; see the file COPYING.
22 If not, write to the Free Software Foundation,
23 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
24
25 #include "diff.h"
26 #include <error.h>
27 #include <exclude.h>
28 #include <setjmp.h>
29 #include <xalloc.h>
30
31 /* Read the directory named by DIR and store into DIRDATA a sorted vector
32 of filenames for its contents. DIR->desc == -1 means this directory is
33 known to be nonexistent, so set DIRDATA to an empty vector.
34 Return -1 (setting errno) if error, 0 otherwise. */
35
36 struct dirdata
37 {
38 size_t nnames; /* Number of names. */
39 char const **names; /* Sorted names of files in dir, followed by 0. */
40 char *data; /* Allocated storage for file names. */
41 };
42
43 /* Whether file names in directories should be compared with strcoll. */
44 static bool locale_specific_sorting;
45
46 /* Where to go if strcoll fails. */
47 static jmp_buf failed_strcoll;
48
49 static bool dir_loop (struct comparison const *, int);
50 static int compare_names_for_qsort (void const *, void const *);
51
52
53 /* Read a directory and get its vector of names. */
54
55 static bool
dir_read(struct file_data const * dir,struct dirdata * dirdata)56 dir_read (struct file_data const *dir, struct dirdata *dirdata)
57 {
58 register struct dirent *next;
59 register size_t i;
60
61 /* Address of block containing the files that are described. */
62 char const **names;
63
64 /* Number of files in directory. */
65 size_t nnames;
66
67 /* Allocated and used storage for file name data. */
68 char *data;
69 size_t data_alloc, data_used;
70
71 dirdata->names = 0;
72 dirdata->data = 0;
73 nnames = 0;
74 data = 0;
75
76 if (dir->desc != -1)
77 {
78 /* Open the directory and check for errors. */
79 register DIR *reading = opendir (dir->name);
80 if (!reading)
81 return 0;
82
83 /* Initialize the table of filenames. */
84
85 data_alloc = 512;
86 data_used = 0;
87 dirdata->data = data = xmalloc (data_alloc);
88
89 /* Read the directory entries, and insert the subfiles
90 into the `data' table. */
91
92 while ((errno = 0, (next = readdir (reading)) != 0))
93 {
94 char *d_name = next->d_name;
95 size_t d_size = NAMLEN (next) + 1;
96
97 /* Ignore "." and "..". */
98 if (d_name[0] == '.'
99 && (d_name[1] == 0 || (d_name[1] == '.' && d_name[2] == 0)))
100 continue;
101
102 if (excluded_filename (excluded, d_name))
103 continue;
104
105 while (data_alloc < data_used + d_size)
106 {
107 if (PTRDIFF_MAX / 2 <= data_alloc)
108 xalloc_die ();
109 dirdata->data = data = xrealloc (data, data_alloc *= 2);
110 }
111
112 memcpy (data + data_used, d_name, d_size);
113 data_used += d_size;
114 nnames++;
115 }
116 if (errno)
117 {
118 int e = errno;
119 closedir (reading);
120 errno = e;
121 return 0;
122 }
123 #if CLOSEDIR_VOID
124 closedir (reading);
125 #else
126 if (closedir (reading) != 0)
127 return 0;
128 #endif
129 }
130
131 /* Create the `names' table from the `data' table. */
132 if (PTRDIFF_MAX / sizeof *names - 1 <= nnames)
133 xalloc_die ();
134 dirdata->names = names = xmalloc ((nnames + 1) * sizeof *names);
135 dirdata->nnames = nnames;
136 for (i = 0; i < nnames; i++)
137 {
138 names[i] = data;
139 data += strlen (data) + 1;
140 }
141 names[nnames] = 0;
142 return 1;
143 }
144
145 /* Compare file names, returning a value compatible with strcmp. */
146
147 static int
compare_names(char const * name1,char const * name2)148 compare_names (char const *name1, char const *name2)
149 {
150 if (ignore_file_name_case)
151 {
152 int r = strcasecmp (name1, name2);
153 if (r)
154 return r;
155 }
156
157 if (locale_specific_sorting)
158 {
159 int r;
160 errno = 0;
161 r = strcoll (name1, name2);
162 if (errno)
163 {
164 error (0, errno, _("cannot compare file names `%s' and `%s'"),
165 name1, name2);
166 longjmp (failed_strcoll, 1);
167 }
168 if (r)
169 return r;
170 }
171
172 return file_name_cmp (name1, name2);
173 }
174
175 /* A wrapper for compare_names suitable as an argument for qsort. */
176
177 static int
compare_names_for_qsort(void const * file1,void const * file2)178 compare_names_for_qsort (void const *file1, void const *file2)
179 {
180 char const *const *f1 = file1;
181 char const *const *f2 = file2;
182 return compare_names (*f1, *f2);
183 }
184
185 /* Compare the contents of two directories named in CMP.
186 This is a top-level routine; it does everything necessary for diff
187 on two directories.
188
189 CMP->file[0].desc == -1 says directory CMP->file[0] doesn't exist,
190 but pretend it is empty. Likewise for CMP->file[1].
191
192 HANDLE_FILE is a caller-provided subroutine called to handle each file.
193 It gets three operands: CMP, name of file in dir 0, name of file in dir 1.
194 These names are relative to the original working directory.
195
196 For a file that appears in only one of the dirs, one of the name-args
197 to HANDLE_FILE is zero.
198
199 Returns the maximum of all the values returned by HANDLE_FILE,
200 or EXIT_TROUBLE if trouble is encountered in opening files. */
201
202 int
diff_dirs(struct comparison const * cmp,int (* handle_file)(struct comparison const *,char const *,char const *))203 diff_dirs (struct comparison const *cmp,
204 int (*handle_file) (struct comparison const *,
205 char const *, char const *))
206 {
207 struct dirdata dirdata[2];
208 int volatile val = EXIT_SUCCESS;
209 int i;
210
211 if ((cmp->file[0].desc == -1 || dir_loop (cmp, 0))
212 && (cmp->file[1].desc == -1 || dir_loop (cmp, 1)))
213 {
214 error (0, 0, "%s: recursive directory loop",
215 cmp->file[cmp->file[0].desc == -1].name);
216 return EXIT_TROUBLE;
217 }
218
219 /* Get contents of both dirs. */
220 for (i = 0; i < 2; i++)
221 if (! dir_read (&cmp->file[i], &dirdata[i]))
222 {
223 perror_with_name (cmp->file[i].name);
224 val = EXIT_TROUBLE;
225 }
226
227 if (val == EXIT_SUCCESS)
228 {
229 char const **volatile names[2];
230 names[0] = dirdata[0].names;
231 names[1] = dirdata[1].names;
232
233 /* Use locale-specific sorting if possible, else native byte order. */
234 locale_specific_sorting = 1;
235 if (setjmp (failed_strcoll))
236 locale_specific_sorting = 0;
237
238 /* Sort the directories. */
239 for (i = 0; i < 2; i++)
240 qsort (names[i], dirdata[i].nnames, sizeof *dirdata[i].names,
241 compare_names_for_qsort);
242
243 /* If `-S name' was given, and this is the topmost level of comparison,
244 ignore all file names less than the specified starting name. */
245
246 if (starting_file && ! cmp->parent)
247 {
248 while (*names[0] && compare_names (*names[0], starting_file) < 0)
249 names[0]++;
250 while (*names[1] && compare_names (*names[1], starting_file) < 0)
251 names[1]++;
252 }
253
254 /* Loop while files remain in one or both dirs. */
255 while (*names[0] || *names[1])
256 {
257 /* Compare next name in dir 0 with next name in dir 1.
258 At the end of a dir,
259 pretend the "next name" in that dir is very large. */
260 int nameorder = (!*names[0] ? 1 : !*names[1] ? -1
261 : compare_names (*names[0], *names[1]));
262 int v1 = (*handle_file) (cmp,
263 0 < nameorder ? 0 : *names[0]++,
264 nameorder < 0 ? 0 : *names[1]++);
265 if (val < v1)
266 val = v1;
267 }
268 }
269
270 for (i = 0; i < 2; i++)
271 {
272 if (dirdata[i].names)
273 free (dirdata[i].names);
274 if (dirdata[i].data)
275 free (dirdata[i].data);
276 }
277
278 return val;
279 }
280
281 /* Return nonzero if CMP is looping recursively in argument I. */
282
283 static bool
dir_loop(struct comparison const * cmp,int i)284 dir_loop (struct comparison const *cmp, int i)
285 {
286 struct comparison const *p = cmp;
287 while ((p = p->parent))
288 if (0 < same_file (&p->file[i].stat, &cmp->file[i].stat))
289 return 1;
290 return 0;
291 }
292