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33 * $FreeBSD: src/lib/libc/gen/scandir.c,v 1.5.6.1 2001/03/05 09:52:13 obrien Exp $
34 * $DragonFly: src/lib/libc/gen/scandir.c,v 1.6 2005/04/26 08:54:59 joerg Exp $
36 * @(#)scandir.c 8.3 (Berkeley) 1/2/94
40 * Scan the directory dirname calling select to make a list of selected
41 * directory entries then sort using qsort and compare routine dcomp.
42 * Returns the number of entries and a pointer to a list of pointers to
43 * struct dirent (through namelist). Returns -1 if there were any errors.
46 #include "namespace.h"
47 #include <sys/types.h>
53 #include "un-namespace.h"
56 * The DIRSIZ macro is the minimum record length which will hold the directory
57 * entry. This requires the amount of space in struct dirent without the
58 * d_name field, plus enough space for the name and a terminating nul byte
59 * (dp->d_namlen + 1), rounded up to a 4 byte boundary.
63 ((sizeof(struct dirent) - sizeof(dp)->d_name) + \
64 (((dp)->d_namlen + 1 + 3) &~ 3))
67 scandir(const char *dirname, struct dirent ***namelist,
68 int (*select)(struct dirent *), int (*dcomp)(const void *, const void *))
70 struct dirent *d, *p, **names = NULL;
71 size_t arraysz, nitems = 0;
75 if ((dirp = opendir(dirname)) == NULL)
77 if (_fstat(dirp->dd_fd, &stb) < 0)
81 * Estimate the array size by taking the size of the directory file
82 * and dividing it by a multiple of the minimum size entry.
83 * Ensure that the size does fit into memory without overflooding.
85 if (stb.st_size / 24 > SIZE_T_MAX)
87 arraysz = stb.st_size / 24;
88 names = (struct dirent **)malloc(arraysz * sizeof(struct dirent *));
92 while ((d = readdir(dirp)) != NULL) {
93 if (select != NULL && !(*select)(d))
94 continue; /* just selected names */
96 * Make a minimum size copy of the data
98 p = (struct dirent *)malloc(DIRSIZ(d));
101 p->d_fileno = d->d_fileno;
102 p->d_type = d->d_type;
103 p->d_reclen = d->d_reclen;
104 p->d_namlen = d->d_namlen;
105 bcopy(d->d_name, p->d_name, p->d_namlen + 1);
107 * Check to make sure the array has space left and
108 * realloc the maximum size.
110 if (nitems >= arraysz) {
111 const int inc = 10; /* increase by this much */
112 struct dirent **names2;
114 names2 = (struct dirent **)realloc((char *)names,
115 (arraysz + inc) * sizeof(struct dirent *));
116 if (names2 == NULL) {
126 if (nitems && dcomp != NULL)
127 qsort(names, nitems, sizeof(struct dirent *), dcomp);
133 free(names[--nitems]);
140 * Alphabetic order comparison routine for those who want it.
143 alphasort(const void *d1, const void *d2)
145 return(strcmp((*(const struct dirent * const *)d1)->d_name,
146 (*(const struct dirent * const *)d2)->d_name));