gen/FreeBSD/scandir.c

   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
  34 #if defined(LIBC_SCCS) && !defined(lint)
  35 static char sccsid[] = "@(#)scandir.c   8.3 (Berkeley) 1/2/94";
  36 #endif /* LIBC_SCCS and not lint */
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD: src/lib/libc/gen/scandir.c,v 1.7 2002/02/01 01:32:19 obrien Exp $");
  39
  40 /*
  41  * Scan the directory dirname calling select to make a list of selected
  42  * directory entries then sort using qsort and compare routine dcomp.
  43  * Returns the number of entries and a pointer to a list of pointers to
  44  * struct dirent (through namelist). Returns -1 if there were any errors.
  45  */
  46
  47 #include "namespace.h"
  48 #include <sys/types.h>
  49 #include <sys/stat.h>
  50 #include <dirent.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(dirname, namelist, select, dcomp)
  68         const char *dirname;
  69         struct dirent ***namelist;
  70         int (*select)(struct dirent *);
  71         int (*dcomp)(const void *, const void *);
  72 {
  73         struct dirent *d, *p, **names = NULL;
  74         size_t nitems = 0;
  75         struct stat stb;
  76         long arraysz;
  77         DIR *dirp;
  78
  79         if ((dirp = opendir(dirname)) == NULL)
  80                 return(-1);
  81         if (_fstat(dirp->dd_fd, &stb) < 0)
  82                 goto fail;
  83
  84         /*
  85          * estimate the array size by taking the size of the directory file
  86          * and dividing it by a multiple of the minimum size entry.
  87          */
  88         arraysz = (stb.st_size / 24);
  89         names = (struct dirent **)malloc(arraysz * sizeof(struct dirent *));
  90         if (names == NULL)
  91                 goto fail;
  92
  93         while ((d = readdir(dirp)) != NULL) {
  94                 if (select != NULL && !(*select)(d))
  95                         continue;       /* just selected names */
  96                 /*
  97                  * Make a minimum size copy of the data
  98                  */
  99                 p = (struct dirent *)malloc(DIRSIZ(d));
 100                 if (p == NULL)
 101                         goto fail;
 102                 p->d_fileno = d->d_fileno;
 103                 p->d_type = d->d_type;
 104                 p->d_reclen = d->d_reclen;
 105                 p->d_namlen = d->d_namlen;
 106                 bcopy(d->d_name, p->d_name, p->d_namlen + 1);
 107                 /*
 108                  * Check to make sure the array has space left and
 109                  * realloc the maximum size.
 110                  */
 111                 if (nitems >= arraysz) {
 112                         const int inc = 10;     /* increase by this much */
 113                         struct dirent **names2;
 114
 115                         names2 = (struct dirent **)realloc((char *)names,
 116                                 (arraysz + inc) * sizeof(struct dirent *));
 117                         if (names2 == NULL) {
 118                                 free(p);
 119                                 goto fail;
 120                         }
 121                         names = names2;
 122                         arraysz += inc;
 123                 }
 124                 names[nitems++] = p;
 125         }
 126         closedir(dirp);
 127         if (nitems && dcomp != NULL)
 128                 qsort(names, nitems, sizeof(struct dirent *), dcomp);
 129         *namelist = names;
 130         return(nitems);
 131
 132 fail:
 133         while (nitems > 0)
 134                 free(names[--nitems]);
 135         free(names);
 136         closedir(dirp);
 137         return -1;
 138 }
 139
 140 /*
 141  * Alphabetic order comparison routine for those who want it.
 142  */
 143 int
 144 alphasort(d1, d2)
 145         const void *d1;
 146         const void *d2;
 147 {
 148         return(strcmp((*(struct dirent **)d1)->d_name,
 149             (*(struct dirent **)d2)->d_name));
 150 }