1 /* Read, sort and compare two directories. Used for GNU DIFF.
2 Copyright (C) 1988, 1989, 1992, 1993, 1994 Free Software Foundation, Inc.
3
4 This file is part of GNU DIFF.
5
6 GNU DIFF 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 GNU DIFF 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 GNU DIFF; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
19
20 #include "diff.h"
21
22 /* Read the directory named by DIR and store into DIRDATA a sorted vector
23 of filenames for its contents. DIR->desc == -1 means this directory is
24 known to be nonexistent, so set DIRDATA to an empty vector.
25 Return -1 (setting errno) if error, 0 otherwise. */
26
27 struct dirdata
28 {
29 char const **names; /* Sorted names of files in dir, 0-terminated. */
30 char *data; /* Allocated storage for file names. */
31 };
32
33 static int compare_names PARAMS((void const *, void const *));
34 static int dir_sort PARAMS((struct file_data const *, struct dirdata *));
35
36 static int
dir_sort(dir,dirdata)37 dir_sort (dir, dirdata)
38 struct file_data const *dir;
39 struct dirdata *dirdata;
40 {
41 register struct dirent *next;
42 register int i;
43
44 /* Address of block containing the files that are described. */
45 char const **names;
46
47 /* Number of files in directory. */
48 size_t nnames;
49
50 /* Allocated and used storage for file name data. */
51 char *data;
52 size_t data_alloc, data_used;
53
54 dirdata->names = 0;
55 dirdata->data = 0;
56 nnames = 0;
57 data = 0;
58
59 if (dir->desc != -1)
60 {
61 /* Open the directory and check for errors. */
62 register DIR *reading = opendir (dir->name);
63 if (!reading)
64 return -1;
65
66 /* Initialize the table of filenames. */
67
68 data_alloc = max (1, (size_t) dir->stat.st_size);
69 data_used = 0;
70 dirdata->data = data = xmalloc (data_alloc);
71
72 /* Read the directory entries, and insert the subfiles
73 into the `data' table. */
74
75 while ((errno = 0, (next = readdir (reading)) != 0))
76 {
77 char *d_name = next->d_name;
78 size_t d_size = NAMLEN (next) + 1;
79
80 /* Ignore the files `.' and `..' */
81 if (d_name[0] == '.'
82 && (d_name[1] == 0 || (d_name[1] == '.' && d_name[2] == 0)))
83 continue;
84
85 if (excluded_filename (d_name))
86 continue;
87
88 while (data_alloc < data_used + d_size)
89 dirdata->data = data = xrealloc (data, data_alloc *= 2);
90 memcpy (data + data_used, d_name, d_size);
91 data_used += d_size;
92 nnames++;
93 }
94 if (errno)
95 {
96 int e = errno;
97 closedir (reading);
98 errno = e;
99 return -1;
100 }
101 #if CLOSEDIR_VOID
102 closedir (reading);
103 #else
104 if (closedir (reading) != 0)
105 return -1;
106 #endif
107 }
108
109 /* Create the `names' table from the `data' table. */
110 dirdata->names = names = (char const **) xmalloc (sizeof (char *)
111 * (nnames + 1));
112 for (i = 0; i < nnames; i++)
113 {
114 names[i] = data;
115 data += strlen (data) + 1;
116 }
117 names[nnames] = 0;
118
119 /* Sort the table. */
120 qsort (names, nnames, sizeof (char *), compare_names);
121
122 return 0;
123 }
124
125 /* Sort the files now in the table. */
126
127 static int
compare_names(file1,file2)128 compare_names (file1, file2)
129 void const *file1, *file2;
130 {
131 return filename_cmp (* (char const *const *) file1,
132 * (char const *const *) file2);
133 }
134
135 /* Compare the contents of two directories named in FILEVEC[0] and FILEVEC[1].
136 This is a top-level routine; it does everything necessary for diff
137 on two directories.
138
139 FILEVEC[0].desc == -1 says directory FILEVEC[0] doesn't exist,
140 but pretend it is empty. Likewise for FILEVEC[1].
141
142 HANDLE_FILE is a caller-provided subroutine called to handle each file.
143 It gets five operands: dir and name (rel to original working dir) of file
144 in dir 0, dir and name pathname of file in dir 1, and the recursion depth.
145
146 For a file that appears in only one of the dirs, one of the name-args
147 to HANDLE_FILE is zero.
148
149 DEPTH is the current depth in recursion, used for skipping top-level
150 files by the -S option.
151
152 Returns the maximum of all the values returned by HANDLE_FILE,
153 or 2 if trouble is encountered in opening files. */
154
155 int
diff_dirs(filevec,handle_file,depth)156 diff_dirs (filevec, handle_file, depth)
157 struct file_data const filevec[];
158 int (*handle_file) PARAMS((char const *, char const *, char const *, char const *, int));
159 int depth;
160 {
161 struct dirdata dirdata[2];
162 int val = 0; /* Return value. */
163 int i;
164
165 /* Get sorted contents of both dirs. */
166 for (i = 0; i < 2; i++)
167 if (dir_sort (&filevec[i], &dirdata[i]) != 0)
168 {
169 perror_with_name (filevec[i].name);
170 val = 2;
171 }
172
173 if (val == 0)
174 {
175 register char const * const *names0 = dirdata[0].names;
176 register char const * const *names1 = dirdata[1].names;
177 char const *name0 = filevec[0].name;
178 char const *name1 = filevec[1].name;
179
180 /* If `-S name' was given, and this is the topmost level of comparison,
181 ignore all file names less than the specified starting name. */
182
183 if (dir_start_file && depth == 0)
184 {
185 while (*names0 && filename_cmp (*names0, dir_start_file) < 0)
186 names0++;
187 while (*names1 && filename_cmp (*names1, dir_start_file) < 0)
188 names1++;
189 }
190
191 /* Loop while files remain in one or both dirs. */
192 while (*names0 || *names1)
193 {
194 /* Compare next name in dir 0 with next name in dir 1.
195 At the end of a dir,
196 pretend the "next name" in that dir is very large. */
197 int nameorder = (!*names0 ? 1 : !*names1 ? -1
198 : filename_cmp (*names0, *names1));
199 int v1 = (*handle_file) (name0, 0 < nameorder ? 0 : *names0++,
200 name1, nameorder < 0 ? 0 : *names1++,
201 depth + 1);
202 if (v1 > val)
203 val = v1;
204 }
205 }
206
207 for (i = 0; i < 2; i++)
208 {
209 if (dirdata[i].names)
210 free (dirdata[i].names);
211 if (dirdata[i].data)
212 free (dirdata[i].data);
213 }
214
215 return val;
216 }
217