1 | /* Logic guts of scandir*. |
2 | Copyright (C) 1992-2018 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <dirent.h> |
20 | #include <errno.h> |
21 | #include <stdlib.h> |
22 | #include <string.h> |
23 | #include <libc-lock.h> |
24 | |
25 | #ifndef SCANDIR_TAIL |
26 | # define SCANDIR_TAIL __scandir_tail |
27 | # define READDIR __readdir |
28 | # define DIRENT_TYPE struct dirent |
29 | #endif |
30 | |
31 | int |
32 | SCANDIR_TAIL (DIR *dp, |
33 | DIRENT_TYPE ***namelist, |
34 | int (*select) (const DIRENT_TYPE *), |
35 | int (*cmp) (const DIRENT_TYPE **, const DIRENT_TYPE **)) |
36 | { |
37 | if (dp == NULL) |
38 | return -1; |
39 | |
40 | int save = errno; |
41 | __set_errno (0); |
42 | |
43 | int result; |
44 | struct scandir_cancel_struct c = { .dp = dp }; |
45 | __libc_cleanup_push (&__scandir_cancel_handler, &c); |
46 | |
47 | DIRENT_TYPE **v = NULL; |
48 | size_t vsize = 0; |
49 | DIRENT_TYPE *d; |
50 | while ((d = READDIR (dp)) != NULL) |
51 | { |
52 | if (select != NULL) |
53 | { |
54 | int selected = (*select) (d); |
55 | |
56 | /* The SELECT function might have set errno to non-zero on |
57 | success. It was zero before and it needs to be again to |
58 | make the later tests work. */ |
59 | __set_errno (0); |
60 | |
61 | if (!selected) |
62 | continue; |
63 | } |
64 | |
65 | if (__glibc_unlikely (c.cnt == vsize)) |
66 | { |
67 | if (vsize == 0) |
68 | vsize = 10; |
69 | else |
70 | vsize *= 2; |
71 | DIRENT_TYPE **new = realloc (v, vsize * sizeof *v); |
72 | if (new == NULL) |
73 | break; |
74 | c.v = v = new; |
75 | } |
76 | |
77 | size_t dsize = &d->d_name[_D_ALLOC_NAMLEN (d)] - (char *) d; |
78 | DIRENT_TYPE *vnew = malloc (dsize); |
79 | if (vnew == NULL) |
80 | break; |
81 | v[c.cnt++] = (DIRENT_TYPE *) memcpy (vnew, d, dsize); |
82 | |
83 | /* Ignore errors from readdir, malloc or realloc. These functions |
84 | might have set errno to non-zero on success. It was zero before |
85 | and it needs to be again to make the latter tests work. */ |
86 | __set_errno (0); |
87 | } |
88 | |
89 | if (__glibc_likely (errno == 0)) |
90 | { |
91 | __closedir (dp); |
92 | |
93 | /* Sort the list if we have a comparison function to sort with. */ |
94 | if (cmp != NULL) |
95 | qsort (v, c.cnt, sizeof *v, (__compar_fn_t) cmp); |
96 | |
97 | *namelist = v; |
98 | result = c.cnt; |
99 | } |
100 | else |
101 | { |
102 | /* This frees everything and calls closedir. */ |
103 | __scandir_cancel_handler (&c); |
104 | result = -1; |
105 | } |
106 | |
107 | __libc_cleanup_pop (0); |
108 | |
109 | if (result >= 0) |
110 | __set_errno (save); |
111 | return result; |
112 | } |
113 | |