1 /* $OpenBSD: scandir.c,v 1.16 2013/04/17 17:40:35 tedu Exp $ */ 2 /* 3 * Copyright (c) 1983, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 /* 32 * Scan the directory dirname calling select to make a list of selected 33 * directory entries then sort using qsort and compare routine dcomp. 34 * Returns the number of entries and a pointer to a list of pointers to 35 * struct dirent (through namelist). Returns -1 if there were any errors. 36 */ 37 38 #include <sys/param.h> 39 #include <sys/stat.h> 40 #include <dirent.h> 41 #include <errno.h> 42 #include <limits.h> 43 #include <stdlib.h> 44 #include <string.h> 45 #include "telldir.h" 46 47 /* 48 * The DIRSIZ macro is the minimum record length which will hold the directory 49 * entry. This requires the amount of space in struct dirent without the 50 * d_name field, plus enough space for the name and a terminating nul byte 51 * (dp->d_namlen + 1), rounded up to a 4 byte boundary. 52 */ 53 #undef DIRSIZ 54 #define DIRSIZ(dp) \ 55 ((sizeof(struct dirent) - sizeof(dp)->d_name) + \ 56 (((dp)->d_namlen + 1 + 3) &~ 3)) 57 58 int 59 scandir(const char *dirname, struct dirent ***namelist, 60 int (*select)(const struct dirent *), 61 int (*dcomp)(const struct dirent **, const struct dirent **)) 62 { 63 struct dirent *d, *p, **names = NULL; 64 size_t nitems = 0; 65 struct stat stb; 66 long arraysz; 67 DIR *dirp; 68 69 if ((dirp = opendir(dirname)) == NULL) 70 return (-1); 71 if (fstat(dirp->dd_fd, &stb) < 0) 72 goto fail; 73 74 /* 75 * estimate the array size by taking the size of the directory file 76 * and dividing it by a multiple of the minimum size entry. 77 */ 78 arraysz = MAX(stb.st_size / 24, 16); 79 if (arraysz > SIZE_MAX / sizeof(struct dirent *)) { 80 errno = ENOMEM; 81 goto fail; 82 } 83 names = (struct dirent **)calloc(arraysz, sizeof(struct dirent *)); 84 if (names == NULL) 85 goto fail; 86 87 while ((d = readdir(dirp)) != NULL) { 88 if (select != NULL && !(*select)(d)) 89 continue; /* just selected names */ 90 91 /* 92 * Check to make sure the array has space left and 93 * realloc the maximum size. 94 */ 95 if (nitems >= arraysz) { 96 struct dirent **nnames; 97 98 if (fstat(dirp->dd_fd, &stb) < 0) 99 goto fail; 100 101 arraysz *= 2; 102 if (SIZE_MAX / sizeof(struct dirent *) < arraysz) 103 goto fail; 104 nnames = (struct dirent **)realloc((char *)names, 105 arraysz * sizeof(struct dirent *)); 106 if (nnames == NULL) 107 goto fail; 108 109 names = nnames; 110 } 111 112 /* 113 * Make a minimum size copy of the data 114 */ 115 p = (struct dirent *)malloc(DIRSIZ(d)); 116 if (p == NULL) 117 goto fail; 118 119 p->d_ino = d->d_ino; 120 p->d_type = d->d_type; 121 p->d_reclen = d->d_reclen; 122 p->d_namlen = d->d_namlen; 123 bcopy(d->d_name, p->d_name, p->d_namlen + 1); 124 names[nitems++] = p; 125 } 126 closedir(dirp); 127 if (nitems && dcomp != NULL) 128 qsort(names, nitems, sizeof(struct dirent *), 129 (int(*)(const void *, const void *))dcomp); 130 *namelist = names; 131 return (nitems); 132 133 fail: 134 while (nitems > 0) 135 free(names[--nitems]); 136 free(names); 137 closedir(dirp); 138 return (-1); 139 } 140 141 /* 142 * Alphabetic order comparison routine for those who want it. 143 */ 144 int 145 alphasort(const struct dirent **d1, const struct dirent **d2) 146 { 147 return(strcmp((*d1)->d_name, (*d2)->d_name)); 148 } 149