1 /* $NetBSD: scandir.c,v 1.22 2003/08/07 16:42:56 agc 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. 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 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char sccsid[] = "@(#)scandir.c 8.3 (Berkeley) 1/2/94"; 36 #else 37 __RCSID("$NetBSD: scandir.c,v 1.22 2003/08/07 16:42:56 agc Exp $"); 38 #endif 39 #endif /* LIBC_SCCS and not lint */ 40 41 /* 42 * Scan the directory dirname calling select to make a list of selected 43 * directory entries then sort using qsort and compare routine dcomp. 44 * Returns the number of entries and a pointer to a list of pointers to 45 * struct dirent (through namelist). Returns -1 if there were any errors. 46 */ 47 48 #include "namespace.h" 49 #include <sys/types.h> 50 #include <sys/stat.h> 51 52 #include <assert.h> 53 #include <errno.h> 54 #include <dirent.h> 55 #include <stdlib.h> 56 #include <string.h> 57 58 #ifdef __weak_alias 59 __weak_alias(scandir,_scandir) 60 __weak_alias(alphasort,_alphasort) 61 #endif 62 63 /* 64 * The DIRSIZ macro is the minimum record length which will hold the directory 65 * entry. This requires the amount of space in struct dirent without the 66 * d_name field, plus enough space for the name and a terminating nul byte 67 * (dp->d_namlen + 1), rounded up to a 4 byte boundary. 68 */ 69 #undef DIRSIZ 70 #define DIRSIZ(dp) \ 71 ((sizeof(struct dirent) - sizeof(dp)->d_name) + \ 72 (((dp)->d_namlen + 1 + 3) &~ 3)) 73 74 int 75 scandir(dirname, namelist, select, dcomp) 76 const char *dirname; 77 struct dirent ***namelist; 78 int (*select) __P((const struct dirent *)); 79 int (*dcomp) __P((const void *, const void *)); 80 { 81 struct dirent *d, *p, **names, **newnames; 82 size_t nitems, arraysz; 83 struct stat stb; 84 DIR *dirp; 85 86 _DIAGASSERT(dirname != NULL); 87 _DIAGASSERT(namelist != NULL); 88 89 if ((dirp = opendir(dirname)) == NULL) 90 return (-1); 91 if (fstat(dirp->dd_fd, &stb) < 0) 92 goto bad; 93 94 /* 95 * estimate the array size by taking the size of the directory file 96 * and dividing it by a multiple of the minimum size entry. 97 */ 98 arraysz = (size_t)(stb.st_size / 24); 99 names = malloc(arraysz * sizeof(struct dirent *)); 100 if (names == NULL) 101 goto bad; 102 103 nitems = 0; 104 while ((d = readdir(dirp)) != NULL) { 105 if (select != NULL && !(*select)(d)) 106 continue; /* just selected names */ 107 108 /* 109 * Check to make sure the array has space left and 110 * realloc the maximum size. 111 */ 112 if (nitems >= arraysz) { 113 if (fstat(dirp->dd_fd, &stb) < 0) 114 goto bad2; /* just might have grown */ 115 arraysz = (size_t)(stb.st_size / 12); 116 newnames = realloc(names, 117 arraysz * sizeof(struct dirent *)); 118 if (newnames == NULL) 119 goto bad2; 120 names = newnames; 121 } 122 123 /* 124 * Make a minimum size copy of the data 125 */ 126 p = (struct dirent *)malloc(DIRSIZ(d)); 127 if (p == NULL) 128 goto bad2; 129 p->d_fileno = d->d_fileno; 130 p->d_reclen = d->d_reclen; 131 p->d_type = d->d_type; 132 p->d_namlen = d->d_namlen; 133 memmove(p->d_name, d->d_name, (size_t)(p->d_namlen + 1)); 134 names[nitems++] = p; 135 } 136 closedir(dirp); 137 if (nitems && dcomp != NULL) 138 qsort(names, nitems, sizeof(struct dirent *), dcomp); 139 *namelist = names; 140 return (nitems); 141 142 bad2: 143 while (nitems-- > 0) 144 free(names[nitems]); 145 free(names); 146 bad: 147 closedir(dirp); 148 return (-1); 149 } 150 151 /* 152 * Alphabetic order comparison routine for those who want it. 153 */ 154 int 155 alphasort(d1, d2) 156 const void *d1; 157 const void *d2; 158 { 159 160 _DIAGASSERT(d1 != NULL); 161 _DIAGASSERT(d2 != NULL); 162 163 return (strcmp((*(const struct dirent *const *)d1)->d_name, 164 (*(const struct dirent *const *)d2)->d_name)); 165 } 166