gen/scandir-fbsd.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 _GENERIC_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
  62 int
  63 scandir(dirname, namelist, select, dcomp)
  64         const char *dirname;
  65         struct dirent ***namelist;
  66         int (*select)(struct dirent *);
  67         int (*dcomp)(const void *, const void *);
  68 {
  69         struct dirent *d, *p, **names = NULL;
  70         size_t nitems = 0;
  71         struct stat stb;
  72         long arraysz;
  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          */
  84         arraysz = (stb.st_size / 24);
  85         names = (struct dirent **)malloc(arraysz * sizeof(struct dirent *));
  86         if (names == NULL)
  87                 goto fail;
  88
  89         while ((d = readdir(dirp)) != NULL) {
  90                 if (select != NULL && !(*select)(d))
  91                         continue;       /* just selected names */
  92                 /*
  93                  * Make a minimum size copy of the data
  94                  */
  95                 p = (struct dirent *)malloc(_GENERIC_DIRSIZ(d));
  96                 if (p == NULL)
  97                         goto fail;
  98                 p->d_fileno = d->d_fileno;
  99                 p->d_type = d->d_type;
 100                 p->d_reclen = d->d_reclen;
 101                 p->d_namlen = d->d_namlen;
 102                 bcopy(d->d_name, p->d_name, p->d_namlen + 1);
 103                 /*
 104                  * Check to make sure the array has space left and
 105                  * realloc the maximum size.
 106                  */
 107                 if (nitems >= arraysz) {
 108                         const int inc = 10;     /* increase by this much */
 109                         struct dirent **names2;
 110
 111                         names2 = (struct dirent **)realloc((char *)names,
 112                                 (arraysz + inc) * sizeof(struct dirent *));
 113                         if (names2 == NULL) {
 114                                 free(p);
 115                                 goto fail;
 116                         }
 117                         names = names2;
 118                         arraysz += inc;
 119                 }
 120                 names[nitems++] = p;
 121         }
 122         closedir(dirp);
 123         if (nitems && dcomp != NULL)
 124                 qsort(names, nitems, sizeof(struct dirent *), dcomp);
 125         *namelist = names;
 126         return(nitems);
 127
 128 fail:
 129         while (nitems > 0)
 130                 free(names[--nitems]);
 131         free(names);
 132         closedir(dirp);
 133         return -1;
 134 }
 135
 136 /*
 137  * Alphabetic order comparison routine for those who want it.
 138  */
 139 int
 140 alphasort(d1, d2)
 141         const void *d1;
 142         const void *d2;
 143 {
 144         return(strcmp((*(struct dirent **)d1)->d_name,
 145             (*(struct dirent **)d2)->d_name));
 146 }