1 /*
2 * Copyright (c) 1983 Regents of the University of California.
3 * 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. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)scandir.c 5.10 (Berkeley) 2/23/91";
36 #endif /* LIBC_SCCS and not lint */
37
38 /*
39 * Scan the directory dirname calling select to make a list of selected
40 * directory entries then sort using qsort and compare routine dcomp.
41 * Returns the number of entries and a pointer to a list of pointers to
42 * struct dirent (through namelist). Returns -1 if there were any errors.
43 */
44
45 #include <sys/types.h>
46 #include <sys/stat.h>
47 #include <dirent.h>
48 #include <stdlib.h>
49 #include <string.h>
50
51 /*
52 * The DIRSIZ macro gives the minimum record length which will hold
53 * the directory entry. This requires the amount of space in struct dirent
54 * without the d_name field, plus enough space for the name with a terminating
55 * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
56 */
57 #undef DIRSIZ
58 #define DIRSIZ(dp) \
59 ((sizeof (struct dirent) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))
60
61 int
scandir(dirname,namelist,select,dcomp)62 scandir(dirname, namelist, select, dcomp)
63 const char *dirname;
64 struct dirent ***namelist;
65 int (*select) __P((struct dirent *));
66 int (*dcomp) __P((const void *, const void *));
67 {
68 register struct dirent *d, *p, **names;
69 register size_t nitems;
70 struct stat stb;
71 long arraysz;
72 DIR *dirp;
73
74 if ((dirp = opendir(dirname)) == NULL)
75 return(-1);
76 if (fstat(dirp->dd_fd, &stb) < 0)
77 return(-1);
78
79 /*
80 * estimate the array size by taking the size of the directory file
81 * and dividing it by a multiple of the minimum size entry.
82 */
83 arraysz = (stb.st_size / 24);
84 names = (struct dirent **)malloc(arraysz * sizeof(struct dirent *));
85 if (names == NULL)
86 return(-1);
87
88 nitems = 0;
89 while ((d = readdir(dirp)) != NULL) {
90 if (select != NULL && !(*select)(d))
91 continue; /* just selected names */
92 /*
93 * Make a minimum size copy of the data
94 */
95 p = (struct dirent *)malloc(DIRSIZ(d));
96 if (p == NULL)
97 return(-1);
98 p->d_ino = d->d_ino;
99 p->d_reclen = d->d_reclen;
100 p->d_namlen = d->d_namlen;
101 bcopy(d->d_name, p->d_name, p->d_namlen + 1);
102 /*
103 * Check to make sure the array has space left and
104 * realloc the maximum size.
105 */
106 if (++nitems >= arraysz) {
107 if (fstat(dirp->dd_fd, &stb) < 0)
108 return(-1); /* just might have grown */
109 arraysz = stb.st_size / 12;
110 names = (struct dirent **)realloc((char *)names,
111 arraysz * sizeof(struct dirent *));
112 if (names == NULL)
113 return(-1);
114 }
115 names[nitems-1] = p;
116 }
117 closedir(dirp);
118 if (nitems && dcomp != NULL)
119 qsort(names, nitems, sizeof(struct dirent *), dcomp);
120 *namelist = names;
121 return(nitems);
122 }
123
124 /*
125 * Alphabetic order comparison routine for those who want it.
126 */
127 int
alphasort(d1,d2)128 alphasort(d1, d2)
129 const void *d1;
130 const void *d2;
131 {
132 return(strcmp((*(struct dirent **)d1)->d_name,
133 (*(struct dirent **)d2)->d_name));
134 }
135