1 /* $NetBSD: scandir.c,v 1.21 2001/11/21 00:48:28 enami Exp $ */ 2 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #if defined(LIBC_SCCS) && !defined(lint) 38 #if 0 39 static char sccsid[] = "@(#)scandir.c 8.3 (Berkeley) 1/2/94"; 40 #else 41 __RCSID("$NetBSD: scandir.c,v 1.21 2001/11/21 00:48:28 enami Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 /* 46 * Scan the directory dirname calling select to make a list of selected 47 * directory entries then sort using qsort and compare routine dcomp. 48 * Returns the number of entries and a pointer to a list of pointers to 49 * struct dirent (through namelist). Returns -1 if there were any errors. 50 */ 51 52 #include "namespace.h" 53 #include <sys/types.h> 54 #include <sys/stat.h> 55 56 #include <assert.h> 57 #include <errno.h> 58 #include <dirent.h> 59 #include <stdlib.h> 60 #include <string.h> 61 62 #ifdef __weak_alias 63 __weak_alias(scandir,_scandir) 64 __weak_alias(alphasort,_alphasort) 65 #endif 66 67 /* 68 * The DIRSIZ macro is the minimum record length which will hold the directory 69 * entry. This requires the amount of space in struct dirent without the 70 * d_name field, plus enough space for the name and a terminating nul byte 71 * (dp->d_namlen + 1), rounded up to a 4 byte boundary. 72 */ 73 #undef DIRSIZ 74 #define DIRSIZ(dp) \ 75 ((sizeof(struct dirent) - sizeof(dp)->d_name) + \ 76 (((dp)->d_namlen + 1 + 3) &~ 3)) 77 78 int 79 scandir(dirname, namelist, select, dcomp) 80 const char *dirname; 81 struct dirent ***namelist; 82 int (*select) __P((const struct dirent *)); 83 int (*dcomp) __P((const void *, const void *)); 84 { 85 struct dirent *d, *p, **names, **newnames; 86 size_t nitems, arraysz; 87 struct stat stb; 88 DIR *dirp; 89 90 _DIAGASSERT(dirname != NULL); 91 _DIAGASSERT(namelist != NULL); 92 93 if ((dirp = opendir(dirname)) == NULL) 94 return (-1); 95 if (fstat(dirp->dd_fd, &stb) < 0) 96 goto bad; 97 98 /* 99 * estimate the array size by taking the size of the directory file 100 * and dividing it by a multiple of the minimum size entry. 101 */ 102 arraysz = (size_t)(stb.st_size / 24); 103 names = malloc(arraysz * sizeof(struct dirent *)); 104 if (names == NULL) 105 goto bad; 106 107 nitems = 0; 108 while ((d = readdir(dirp)) != NULL) { 109 if (select != NULL && !(*select)(d)) 110 continue; /* just selected names */ 111 112 /* 113 * Check to make sure the array has space left and 114 * realloc the maximum size. 115 */ 116 if (nitems >= arraysz) { 117 if (fstat(dirp->dd_fd, &stb) < 0) 118 goto bad2; /* just might have grown */ 119 arraysz = (size_t)(stb.st_size / 12); 120 newnames = realloc(names, 121 arraysz * sizeof(struct dirent *)); 122 if (newnames == NULL) 123 goto bad2; 124 names = newnames; 125 } 126 127 /* 128 * Make a minimum size copy of the data 129 */ 130 p = (struct dirent *)malloc(DIRSIZ(d)); 131 if (p == NULL) 132 goto bad2; 133 p->d_fileno = d->d_fileno; 134 p->d_reclen = d->d_reclen; 135 p->d_type = d->d_type; 136 p->d_namlen = d->d_namlen; 137 memmove(p->d_name, d->d_name, (size_t)(p->d_namlen + 1)); 138 names[nitems++] = p; 139 } 140 closedir(dirp); 141 if (nitems && dcomp != NULL) 142 qsort(names, nitems, sizeof(struct dirent *), dcomp); 143 *namelist = names; 144 return (nitems); 145 146 bad2: 147 while (nitems-- > 0) 148 free(names[nitems]); 149 free(names); 150 bad: 151 closedir(dirp); 152 return (-1); 153 } 154 155 /* 156 * Alphabetic order comparison routine for those who want it. 157 */ 158 int 159 alphasort(d1, d2) 160 const void *d1; 161 const void *d2; 162 { 163 164 _DIAGASSERT(d1 != NULL); 165 _DIAGASSERT(d2 != NULL); 166 167 return (strcmp((*(const struct dirent *const *)d1)->d_name, 168 (*(const struct dirent *const *)d2)->d_name)); 169 } 170