Line data Source code
1 : /* savedir.c -- save the list of files in a directory in a string
2 :
3 : Copyright (C) 1990, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005,
4 : 2006 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 3 of the License, or
9 : (at your option) 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. If not, see <http://www.gnu.org/licenses/>. */
18 :
19 : /* Written by David MacKenzie <djm@gnu.ai.mit.edu>. */
20 :
21 : #include <config.h>
22 :
23 : #include "savedir.h"
24 :
25 : #include <sys/types.h>
26 :
27 : #include <errno.h>
28 :
29 : #include <dirent.h>
30 : #ifndef _D_EXACT_NAMLEN
31 : # define _D_EXACT_NAMLEN(dp) strlen ((dp)->d_name)
32 : #endif
33 :
34 : #include <stddef.h>
35 : #include <stdlib.h>
36 : #include <string.h>
37 :
38 : #include "openat.h"
39 : #include "xalloc.h"
40 :
41 : #ifndef NAME_SIZE_DEFAULT
42 : # define NAME_SIZE_DEFAULT 512
43 : #endif
44 :
45 : /* The results of opendir() in this file are not used with dirfd and fchdir,
46 : therefore save some unnecessary work in fchdir.c. */
47 : #undef opendir
48 : #undef closedir
49 :
50 : /* Return a freshly allocated string containing the file names
51 : in directory DIRP, separated by '\0' characters;
52 : the end is marked by two '\0' characters in a row.
53 : Return NULL (setting errno) if DIRP cannot be read or closed.
54 : If DIRP is NULL, return NULL without affecting errno. */
55 :
56 : static char *
57 3 : savedirstream (DIR *dirp)
58 : {
59 : char *name_space;
60 3 : size_t allocated = NAME_SIZE_DEFAULT;
61 3 : size_t used = 0;
62 : int save_errno;
63 :
64 3 : if (dirp == NULL)
65 0 : return NULL;
66 :
67 3 : name_space = xmalloc (allocated);
68 :
69 : for (;;)
70 1016 : {
71 : struct dirent const *dp;
72 : char const *entry;
73 :
74 1019 : errno = 0;
75 1019 : dp = readdir (dirp);
76 1019 : if (! dp)
77 3 : break;
78 :
79 : /* Skip "", ".", and "..". "" is returned by at least one buggy
80 : implementation: Solaris 2.4 readdir on NFS file systems. */
81 1016 : entry = dp->d_name;
82 1016 : if (entry[entry[0] != '.' ? 0 : entry[1] != '.' ? 1 : 2] != '\0')
83 : {
84 1010 : size_t entry_size = _D_EXACT_NAMLEN (dp) + 1;
85 1010 : if (used + entry_size < used)
86 0 : xalloc_die ();
87 1010 : if (allocated <= used + entry_size)
88 : {
89 : do
90 : {
91 9 : if (2 * allocated < allocated)
92 0 : xalloc_die ();
93 9 : allocated *= 2;
94 : }
95 9 : while (allocated <= used + entry_size);
96 :
97 9 : name_space = xrealloc (name_space, allocated);
98 : }
99 1010 : memcpy (name_space + used, entry, entry_size);
100 1010 : used += entry_size;
101 : }
102 : }
103 3 : name_space[used] = '\0';
104 3 : save_errno = errno;
105 3 : if (closedir (dirp) != 0)
106 0 : save_errno = errno;
107 3 : if (save_errno != 0)
108 : {
109 0 : free (name_space);
110 0 : errno = save_errno;
111 0 : return NULL;
112 : }
113 3 : return name_space;
114 : }
115 :
116 : /* Return a freshly allocated string containing the file names
117 : in directory DIR, separated by '\0' characters;
118 : the end is marked by two '\0' characters in a row.
119 : Return NULL (setting errno) if DIR cannot be opened, read, or closed. */
120 :
121 : char *
122 3 : savedir (char const *dir)
123 : {
124 3 : return savedirstream (opendir (dir));
125 : }
126 :
127 : /* Return a freshly allocated string containing the file names
128 : in directory FD, separated by '\0' characters;
129 : the end is marked by two '\0' characters in a row.
130 : Return NULL (setting errno) if FD cannot be read or closed. */
131 :
132 : char *
133 0 : fdsavedir (int fd)
134 : {
135 0 : return savedirstream (fdopendir (fd));
136 : }
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