xref: /freebsd/lib/libc/gen/scandir.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1983, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __SCCSID("@(#)scandir.c	8.3 (Berkeley) 1/2/94");
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 <dirent.h>
43 #include <fcntl.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47 #include "un-namespace.h"
48 
49 #ifdef	I_AM_SCANDIR_B
50 #include "block_abi.h"
51 #define	SELECT(x)	CALL_BLOCK(select, x)
52 #ifndef __BLOCKS__
53 void qsort_b(void *, size_t, size_t, void *);
54 #endif
55 #else
56 #define	SELECT(x)	select(x)
57 #endif
58 
59 #ifdef I_AM_SCANDIR_B
60 typedef DECLARE_BLOCK(int, select_block, const struct dirent *);
61 typedef DECLARE_BLOCK(int, dcomp_block, const struct dirent **,
62     const struct dirent **);
63 #else
64 static int scandir_thunk_cmp(const void *p1, const void *p2, void *thunk);
65 #endif
66 
67 static int
68 #ifdef I_AM_SCANDIR_B
69 scandir_b_dirp(DIR *dirp, struct dirent ***namelist, select_block select,
70     dcomp_block dcomp)
71 #else
72 scandir_dirp(DIR *dirp, struct dirent ***namelist,
73     int (*select)(const struct dirent *), int (*dcomp)(const struct dirent **,
74     const struct dirent **))
75 #endif
76 {
77 	struct dirent *d, *p, **names = NULL;
78 	size_t arraysz, numitems;
79 
80 	numitems = 0;
81 	arraysz = 32;	/* initial estimate of the array size */
82 	names = (struct dirent **)malloc(arraysz * sizeof(struct dirent *));
83 	if (names == NULL)
84 		goto fail;
85 
86 	while ((d = readdir(dirp)) != NULL) {
87 		if (select != NULL && !SELECT(d))
88 			continue;	/* just selected names */
89 		/*
90 		 * Make a minimum size copy of the data
91 		 */
92 		p = (struct dirent *)malloc(_GENERIC_DIRSIZ(d));
93 		if (p == NULL)
94 			goto fail;
95 		p->d_fileno = d->d_fileno;
96 		p->d_type = d->d_type;
97 		p->d_reclen = d->d_reclen;
98 		p->d_namlen = d->d_namlen;
99 		bcopy(d->d_name, p->d_name, p->d_namlen + 1);
100 		/*
101 		 * Check to make sure the array has space left and
102 		 * realloc the maximum size.
103 		 */
104 		if (numitems >= arraysz) {
105 			struct dirent **names2;
106 
107 			names2 = reallocarray(names, arraysz,
108 			    2 * sizeof(struct dirent *));
109 			if (names2 == NULL) {
110 				free(p);
111 				goto fail;
112 			}
113 			names = names2;
114 			arraysz *= 2;
115 		}
116 		names[numitems++] = p;
117 	}
118 	closedir(dirp);
119 	if (numitems && dcomp != NULL)
120 #ifdef I_AM_SCANDIR_B
121 		qsort_b(names, numitems, sizeof(struct dirent *), (void*)dcomp);
122 #else
123 		qsort_r(names, numitems, sizeof(struct dirent *),
124 		    scandir_thunk_cmp, &dcomp);
125 #endif
126 	*namelist = names;
127 	return (numitems);
128 
129 fail:
130 	while (numitems > 0)
131 		free(names[--numitems]);
132 	free(names);
133 	closedir(dirp);
134 	return (-1);
135 }
136 
137 int
138 #ifdef I_AM_SCANDIR_B
139 scandir_b(const char *dirname, struct dirent ***namelist, select_block select,
140     dcomp_block dcomp)
141 #else
142 scandir(const char *dirname, struct dirent ***namelist,
143     int (*select)(const struct dirent *), int (*dcomp)(const struct dirent **,
144     const struct dirent **))
145 #endif
146 {
147 	DIR *dirp;
148 
149 	dirp = opendir(dirname);
150 	if (dirp == NULL)
151 		return (-1);
152 	return (
153 #ifdef I_AM_SCANDIR_B
154 	    scandir_b_dirp
155 #else
156 	    scandir_dirp
157 #endif
158 	    (dirp, namelist, select, dcomp));
159 }
160 
161 #ifndef I_AM_SCANDIR_B
162 int
163 scandirat(int dirfd, const char *dirname, struct dirent ***namelist,
164     int (*select)(const struct dirent *), int (*dcomp)(const struct dirent **,
165     const struct dirent **))
166 {
167 	DIR *dirp;
168 	int fd;
169 
170 	fd = _openat(dirfd, dirname, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
171 	if (fd == -1)
172 		return (-1);
173 	dirp = fdopendir(fd);
174 	if (dirp == NULL) {
175 		_close(fd);
176 		return (-1);
177 	}
178 	return (scandir_dirp(dirp, namelist, select, dcomp));
179 }
180 
181 /*
182  * Alphabetic order comparison routine for those who want it.
183  * POSIX 2008 requires that alphasort() uses strcoll().
184  */
185 int
186 alphasort(const struct dirent **d1, const struct dirent **d2)
187 {
188 
189 	return (strcoll((*d1)->d_name, (*d2)->d_name));
190 }
191 
192 int
193 versionsort(const struct dirent **d1, const struct dirent **d2)
194 {
195 
196 	return (strverscmp((*d1)->d_name, (*d2)->d_name));
197 }
198 
199 static int
200 scandir_thunk_cmp(const void *p1, const void *p2, void *thunk)
201 {
202 	int (*dc)(const struct dirent **, const struct dirent **);
203 
204 	dc = *(int (**)(const struct dirent **, const struct dirent **))thunk;
205 	return (dc((const struct dirent **)p1, (const struct dirent **)p2));
206 }
207 #endif
208