1 /* Read, sort and compare two directories. Used for GNU DIFF.
3 Copyright (C) 1988-1989, 1992-1995, 1998, 2001-2002, 2004, 2006-2007,
4 2009-2010 Free Software Foundation, Inc.
6 This file is part of GNU DIFF.
8 This program is free software: you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation, either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 /* Read the directory named by DIR and store into DIRDATA a sorted vector
28 of filenames for its contents. DIR->desc == -1 means this directory is
29 known to be nonexistent, so set DIRDATA to an empty vector.
30 Return -1 (setting errno) if error, 0 otherwise. */
34 size_t nnames; /* Number of names. */
35 char const **names; /* Sorted names of files in dir, followed by 0. */
36 char *data; /* Allocated storage for file names. */
39 /* Whether file names in directories should be compared with
40 locale-specific sorting. */
41 static bool locale_specific_sorting;
43 /* Where to go if locale-specific sorting fails. */
44 static jmp_buf failed_locale_specific_sorting;
46 static bool dir_loop (struct comparison const *, int);
47 static int compare_names_for_qsort (void const *, void const *);
50 /* Read a directory and get its vector of names. */
53 dir_read (struct file_data const *dir, struct dirdata *dirdata)
55 register struct dirent *next;
58 /* Address of block containing the files that are described. */
61 /* Number of files in directory. */
64 /* Allocated and used storage for file name data. */
66 size_t data_alloc, data_used;
75 /* Open the directory and check for errors. */
76 register DIR *reading = opendir (dir->name);
80 /* Initialize the table of filenames. */
84 dirdata->data = data = xmalloc (data_alloc);
86 /* Read the directory entries, and insert the subfiles
87 into the `data' table. */
89 while ((errno = 0, (next = readdir (reading)) != 0))
91 char *d_name = next->d_name;
92 size_t d_size = _D_EXACT_NAMLEN (next) + 1;
94 /* Ignore "." and "..". */
96 && (d_name[1] == 0 || (d_name[1] == '.' && d_name[2] == 0)))
99 if (excluded_file_name (excluded, d_name))
102 while (data_alloc < data_used + d_size)
104 if (PTRDIFF_MAX / 2 <= data_alloc)
106 dirdata->data = data = xrealloc (data, data_alloc *= 2);
109 memcpy (data + data_used, d_name, d_size);
123 if (closedir (reading) != 0)
128 /* Create the `names' table from the `data' table. */
129 if (PTRDIFF_MAX / sizeof *names - 1 <= nnames)
131 dirdata->names = names = xmalloc ((nnames + 1) * sizeof *names);
132 dirdata->nnames = nnames;
133 for (i = 0; i < nnames; i++)
136 data += strlen (data) + 1;
142 /* Compare file names, returning a value compatible with strcmp. */
145 compare_names (char const *name1, char const *name2)
147 if (locale_specific_sorting)
151 if (ignore_file_name_case)
152 r = strcasecoll (name1, name2);
154 r = strcoll (name1, name2);
157 error (0, errno, _("cannot compare file names `%s' and `%s'"),
159 longjmp (failed_locale_specific_sorting, 1);
164 return (ignore_file_name_case
165 ? strcasecmp (name1, name2)
166 : file_name_cmp (name1, name2));
169 /* A wrapper for compare_names suitable as an argument for qsort. */
172 compare_names_for_qsort (void const *file1, void const *file2)
174 char const *const *f1 = file1;
175 char const *const *f2 = file2;
176 return compare_names (*f1, *f2);
179 /* Compare the contents of two directories named in CMP.
180 This is a top-level routine; it does everything necessary for diff
183 CMP->file[0].desc == -1 says directory CMP->file[0] doesn't exist,
184 but pretend it is empty. Likewise for CMP->file[1].
186 HANDLE_FILE is a caller-provided subroutine called to handle each file.
187 It gets three operands: CMP, name of file in dir 0, name of file in dir 1.
188 These names are relative to the original working directory.
190 For a file that appears in only one of the dirs, one of the name-args
191 to HANDLE_FILE is zero.
193 Returns the maximum of all the values returned by HANDLE_FILE,
194 or EXIT_TROUBLE if trouble is encountered in opening files. */
197 diff_dirs (struct comparison const *cmp,
198 int (*handle_file) (struct comparison const *,
199 char const *, char const *))
201 struct dirdata dirdata[2];
202 int volatile val = EXIT_SUCCESS;
205 if ((cmp->file[0].desc == -1 || dir_loop (cmp, 0))
206 && (cmp->file[1].desc == -1 || dir_loop (cmp, 1)))
208 error (0, 0, _("%s: recursive directory loop"),
209 cmp->file[cmp->file[0].desc == -1].name);
213 /* Get contents of both dirs. */
214 for (i = 0; i < 2; i++)
215 if (! dir_read (&cmp->file[i], &dirdata[i]))
217 perror_with_name (cmp->file[i].name);
221 if (val == EXIT_SUCCESS)
223 char const **volatile names[2];
224 names[0] = dirdata[0].names;
225 names[1] = dirdata[1].names;
227 /* Use locale-specific sorting if possible, else native byte order. */
228 locale_specific_sorting = true;
229 if (setjmp (failed_locale_specific_sorting))
230 locale_specific_sorting = false;
232 /* Sort the directories. */
233 for (i = 0; i < 2; i++)
234 qsort (names[i], dirdata[i].nnames, sizeof *dirdata[i].names,
235 compare_names_for_qsort);
237 /* If `-S name' was given, and this is the topmost level of comparison,
238 ignore all file names less than the specified starting name. */
240 if (starting_file && ! cmp->parent)
242 while (*names[0] && compare_names (*names[0], starting_file) < 0)
244 while (*names[1] && compare_names (*names[1], starting_file) < 0)
248 /* Loop while files remain in one or both dirs. */
249 while (*names[0] || *names[1])
251 /* Compare next name in dir 0 with next name in dir 1.
253 pretend the "next name" in that dir is very large. */
254 int nameorder = (!*names[0] ? 1 : !*names[1] ? -1
255 : compare_names (*names[0], *names[1]));
256 int v1 = (*handle_file) (cmp,
257 0 < nameorder ? 0 : *names[0]++,
258 nameorder < 0 ? 0 : *names[1]++);
264 for (i = 0; i < 2; i++)
266 free (dirdata[i].names);
267 free (dirdata[i].data);
273 /* Return nonzero if CMP is looping recursively in argument I. */
276 dir_loop (struct comparison const *cmp, int i)
278 struct comparison const *p = cmp;
279 while ((p = p->parent))
280 if (0 < same_file (&p->file[i].stat, &cmp->file[i].stat))