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  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static char sccsid[] = "@(#)scandir.c   8.3 (Berkeley) 1/2/94";
  32 #endif /* LIBC_SCCS and not lint */
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD: src/lib/libc/gen/scandir.c,v 1.9 2008/03/16 19:08:53 das Exp $");
  35
  36 /*
  37  * Scan the directory dirname calling select to make a list of selected
  38  * directory entries then sort using qsort and compare routine dcomp.
  39  * Returns the number of entries and a pointer to a list of pointers to
  40  * struct dirent (through namelist). Returns -1 if there were any errors.
  41  */
  42
  43 #include "namespace.h"
  44 #include <dirent.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47 #include "un-namespace.h"
  48
  49 /*
  50  * The DIRSIZ macro is the minimum record length which will hold the directory
  51  * entry.  This requires the amount of space in struct dirent without the
  52  * d_name field, plus enough space for the name and a terminating nul byte
  53  * (dp->d_namlen + 1), rounded up to a 4 byte boundary.
  54  */
  55 #undef DIRSIZ
  56 #define DIRSIZ(dp)                                                      \
  57         ((sizeof(struct dirent) - sizeof(dp)->d_name) +                 \
  58             (((dp)->d_namlen + 1 + 3) &~ 3))
  59
  60 int
  61 scandir(dirname, namelist, select, dcomp)
  62         const char *dirname;
  63         struct dirent ***namelist;
  64         int (*select)(struct dirent *);
  65         int (*dcomp)(const void *, const void *);
  66 {
  67         struct dirent *d, *p, **names = NULL;
  68         size_t nitems = 0;
  69         long arraysz;
  70         DIR *dirp;
  71
  72         if ((dirp = opendir(dirname)) == NULL)
  73                 return(-1);
  74
  75         arraysz = 32;   /* initial estimate of the array size */
  76         names = (struct dirent **)malloc(arraysz * sizeof(struct dirent *));
  77         if (names == NULL)
  78                 goto fail;
  79
  80         while ((d = readdir(dirp)) != NULL) {
  81                 if (select != NULL && !(*select)(d))
  82                         continue;       /* just selected names */
  83                 /*
  84                  * Make a minimum size copy of the data
  85                  */
  86                 p = (struct dirent *)malloc(DIRSIZ(d));
  87                 if (p == NULL)
  88                         goto fail;
  89                 p->d_fileno = d->d_fileno;
  90                 p->d_type = d->d_type;
  91                 p->d_reclen = d->d_reclen;
  92                 p->d_namlen = d->d_namlen;
  93                 bcopy(d->d_name, p->d_name, p->d_namlen + 1);
  94                 /*
  95                  * Check to make sure the array has space left and
  96                  * realloc the maximum size.
  97                  */
  98                 if (nitems >= arraysz) {
  99                         struct dirent **names2;
 100
 101                         names2 = (struct dirent **)realloc((char *)names,
 102                                 (arraysz * 2) * sizeof(struct dirent *));
 103                         if (names2 == NULL) {
 104                                 free(p);
 105                                 goto fail;
 106                         }
 107                         names = names2;
 108                         arraysz *= 2;
 109                 }
 110                 names[nitems++] = p;
 111         }
 112         closedir(dirp);
 113         if (nitems && dcomp != NULL)
 114                 qsort(names, nitems, sizeof(struct dirent *), dcomp);
 115         *namelist = names;
 116         return(nitems);
 117
 118 fail:
 119         while (nitems > 0)
 120                 free(names[--nitems]);
 121         free(names);
 122         closedir(dirp);
 123         return -1;
 124 }
 125
 126 /*
 127  * Alphabetic order comparison routine for those who want it.
 128  */
 129 int
 130 alphasort(d1, d2)
 131         const void *d1;
 132         const void *d2;
 133 {
 134         return(strcmp((*(struct dirent **)d1)->d_name,
 135             (*(struct dirent **)d2)->d_name));
 136 }