1 /*
2 * Copyright (c) 1983, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $FreeBSD: src/lib/libc/gen/scandir.c,v 1.5.6.1 2001/03/05 09:52:13 obrien Exp $
30 *
31 * @(#)scandir.c 8.3 (Berkeley) 1/2/94
32 */
33
34 /*
35 * Scan the directory dirname calling select to make a list of selected
36 * directory entries then sort using qsort and compare routine dcomp.
37 * Returns the number of entries and a pointer to a list of pointers to
38 * struct dirent (through namelist). Returns -1 if there were any errors.
39 */
40
41 #include "namespace.h"
42 #include <sys/types.h>
43 #include <sys/stat.h>
44 #include <dirent.h>
45 #include <limits.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include "un-namespace.h"
49
50 #include "gen_private.h"
51
52 int
scandir(const char * dirname,struct dirent *** namelist,int (* select)(const struct dirent *),int (* dcomp)(const struct dirent **,const struct dirent **))53 scandir(const char *dirname, struct dirent ***namelist,
54 int (*select)(const struct dirent *),
55 int (*dcomp)(const struct dirent **, const struct dirent **))
56 {
57 struct dirent *d, *p, **names = NULL;
58 size_t arraysz, nitems = 0;
59 struct stat stb;
60 DIR *dirp;
61
62 if ((dirp = opendir(dirname)) == NULL)
63 return(-1);
64 if (_fstat(dirp->dd_fd, &stb) < 0)
65 goto fail;
66
67 /*
68 * Estimate the array size by taking the size of the directory file
69 * and dividing it by a multiple of the minimum size entry.
70 * Ensure that the size does fit into memory without overflooding.
71 */
72 if (stb.st_size / 24 > SIZE_T_MAX)
73 goto fail;
74 arraysz = stb.st_size / 24;
75 names = (struct dirent **)malloc(arraysz * sizeof(struct dirent *));
76 if (names == NULL)
77 goto fail;
78
79 while ((d = readdir(dirp)) != NULL) {
80 if (select != NULL && !(*select)(d))
81 continue; /* just selected names */
82 /*
83 * Make a minimum size copy of the data
84 */
85 p = (struct dirent *)malloc(_DIRENT_DIRSIZ(d));
86 if (p == NULL)
87 goto fail;
88 p->d_ino = d->d_ino;
89 p->d_type = d->d_type;
90 p->d_namlen = d->d_namlen;
91 bcopy(d->d_name, p->d_name, p->d_namlen + 1);
92 /*
93 * Check to make sure the array has space left and
94 * realloc the maximum size.
95 */
96 if (nitems >= arraysz) {
97 const int inc = 10; /* increase by this much */
98 struct dirent **names2;
99
100 names2 = (struct dirent **)realloc((char *)names,
101 (arraysz + inc) * sizeof(struct dirent *));
102 if (names2 == NULL) {
103 free(p);
104 goto fail;
105 }
106 names = names2;
107 arraysz += inc;
108 }
109 names[nitems++] = p;
110 }
111 closedir(dirp);
112 if (nitems && dcomp != NULL)
113 qsort(names, nitems, sizeof(struct dirent *),
114 (int (*)(const void *, const void *))dcomp);
115 *namelist = names;
116 return(nitems);
117
118 fail:
119 while (nitems > 0)
120 free(names[--nitems]);
121 free(names);
122 closedir(dirp);
123 return -1;
124 }
125
126 /*
127 * Alphabetic order comparison routine for those who want it.
128 */
129 int
alphasort(const struct dirent ** d1,const struct dirent ** d2)130 alphasort(const struct dirent **d1, const struct dirent **d2)
131 {
132 return(strcmp((*d1)->d_name, (*d2)->d_name));
133 }
134