1 /* $NetBSD: scandir.c,v 1.14 1998/11/13 12:31:51 christos 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 1.14 1998/11/13 12:31:51 christos 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 #include <dirent.h> 56 #include <stdlib.h> 57 #include <string.h> 58 59 #ifdef __weak_alias 60 __weak_alias(scandir,_scandir); 61 __weak_alias(alphasort,_alphasort); 62 #endif 63 64 /* 65 * The DIRSIZ macro is the minimum record length which will hold the directory 66 * entry. This requires the amount of space in struct dirent without the 67 * d_name field, plus enough space for the name and a terminating nul byte 68 * (dp->d_namlen + 1), rounded up to a 4 byte boundary. 69 */ 70 #undef DIRSIZ 71 #define DIRSIZ(dp) \ 72 ((sizeof(struct dirent) - sizeof(dp)->d_name) + \ 73 (((dp)->d_namlen + 1 + 3) &~ 3)) 74 75 int 76 scandir(dirname, namelist, select, dcomp) 77 const char *dirname; 78 struct dirent ***namelist; 79 int (*select) __P((struct dirent *)); 80 int (*dcomp) __P((const void *, const void *)); 81 { 82 struct dirent *d, *p, **names; 83 size_t nitems, arraysz; 84 struct stat stb; 85 DIR *dirp; 86 87 if ((dirp = opendir(dirname)) == NULL) 88 return(-1); 89 if (fstat(dirp->dd_fd, &stb) < 0) 90 return(-1); 91 92 /* 93 * estimate the array size by taking the size of the directory file 94 * and dividing it by a multiple of the minimum size entry. 95 */ 96 arraysz = (size_t)(stb.st_size / 24); 97 names = malloc(arraysz * sizeof(struct dirent *)); 98 if (names == NULL) 99 return(-1); 100 101 nitems = 0; 102 while ((d = readdir(dirp)) != NULL) { 103 if (select != NULL && !(*select)(d)) 104 continue; /* just selected names */ 105 /* 106 * Make a minimum size copy of the data 107 */ 108 p = (struct dirent *)malloc(DIRSIZ(d)); 109 if (p == NULL) 110 return(-1); 111 p->d_fileno = d->d_fileno; 112 p->d_reclen = d->d_reclen; 113 p->d_type = d->d_type; 114 p->d_namlen = d->d_namlen; 115 memmove(p->d_name, d->d_name, (size_t)(p->d_namlen + 1)); 116 /* 117 * Check to make sure the array has space left and 118 * realloc the maximum size. 119 */ 120 if (++nitems >= arraysz) { 121 if (fstat(dirp->dd_fd, &stb) < 0) 122 return(-1); /* just might have grown */ 123 arraysz = (size_t)(stb.st_size / 12); 124 names = realloc(names, 125 arraysz * sizeof(struct dirent *)); 126 if (names == NULL) 127 return(-1); 128 } 129 names[nitems-1] = p; 130 } 131 closedir(dirp); 132 if (nitems && dcomp != NULL) 133 qsort(names, nitems, sizeof(struct dirent *), dcomp); 134 *namelist = names; 135 return(nitems); 136 } 137 138 /* 139 * Alphabetic order comparison routine for those who want it. 140 */ 141 int 142 alphasort(d1, d2) 143 const void *d1; 144 const void *d2; 145 { 146 return(strcmp((*(const struct dirent *const *)d1)->d_name, 147 (*(const struct dirent *const *)d2)->d_name)); 148 } 149