1 /* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. 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 * $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 $ 35 * 36 * @(#)scandir.c 8.3 (Berkeley) 1/2/94 37 */ 38 39 /* 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. 44 */ 45 46 #include "namespace.h" 47 #include <sys/types.h> 48 #include <sys/stat.h> 49 #include <dirent.h> 50 #include <limits.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include "un-namespace.h" 54 55 /* 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. 60 */ 61 #undef DIRSIZ 62 #define DIRSIZ(dp) \ 63 ((sizeof(struct dirent) - sizeof(dp)->d_name) + \ 64 (((dp)->d_namlen + 1 + 3) &~ 3)) 65 66 int 67 scandir(const char *dirname, struct dirent ***namelist, 68 int (*select)(struct dirent *), int (*dcomp)(const void *, const void *)) 69 { 70 struct dirent *d, *p, **names = NULL; 71 size_t arraysz, nitems = 0; 72 struct stat stb; 73 DIR *dirp; 74 75 if ((dirp = opendir(dirname)) == NULL) 76 return(-1); 77 if (_fstat(dirp->dd_fd, &stb) < 0) 78 goto fail; 79 80 /* 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. 84 */ 85 if (stb.st_size / 24 > SIZE_T_MAX) 86 goto fail; 87 arraysz = stb.st_size / 24; 88 names = (struct dirent **)malloc(arraysz * sizeof(struct dirent *)); 89 if (names == NULL) 90 goto fail; 91 92 while ((d = readdir(dirp)) != NULL) { 93 if (select != NULL && !(*select)(d)) 94 continue; /* just selected names */ 95 /* 96 * Make a minimum size copy of the data 97 */ 98 p = (struct dirent *)malloc(DIRSIZ(d)); 99 if (p == NULL) 100 goto fail; 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); 106 /* 107 * Check to make sure the array has space left and 108 * realloc the maximum size. 109 */ 110 if (nitems >= arraysz) { 111 const int inc = 10; /* increase by this much */ 112 struct dirent **names2; 113 114 names2 = (struct dirent **)realloc((char *)names, 115 (arraysz + inc) * sizeof(struct dirent *)); 116 if (names2 == NULL) { 117 free(p); 118 goto fail; 119 } 120 names = names2; 121 arraysz += inc; 122 } 123 names[nitems++] = p; 124 } 125 closedir(dirp); 126 if (nitems && dcomp != NULL) 127 qsort(names, nitems, sizeof(struct dirent *), dcomp); 128 *namelist = names; 129 return(nitems); 130 131 fail: 132 while (nitems > 0) 133 free(names[--nitems]); 134 free(names); 135 closedir(dirp); 136 return -1; 137 } 138 139 /* 140 * Alphabetic order comparison routine for those who want it. 141 */ 142 int 143 alphasort(const void *d1, const void *d2) 144 { 145 return(strcmp((*(const struct dirent * const *)d1)->d_name, 146 (*(const struct dirent * const *)d2)->d_name)); 147 } 148