newlib/libc/sys/sysvi386/scandir.c

   1 /*
   2  * Copyright (c) 1983 Regents of the University of California.
   3  * 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. 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   5.10 (Berkeley) 2/23/91";
  32 #endif /* LIBC_SCCS and not lint */
  33
  34 /*
  35  * Scan the directory dirname calling select to make a list of selected
  36  * directory entries then sort using qsort and compare routine dcomp.
  37  * Returns the number of entries and a pointer to a list of pointers to
  38  * struct dirent (through namelist). Returns -1 if there were any errors.
  39  */
  40
  41 #include <sys/types.h>
  42 #include <sys/stat.h>
  43 #include <dirent.h>
  44 #include <stdlib.h>
  45 #include <string.h>
  46
  47 /*
  48  * The DIRSIZ macro gives the minimum record length which will hold
  49  * the directory entry.  This requires the amount of space in struct dirent
  50  * without the d_name field, plus enough space for the name with a terminating
  51  * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
  52  */
  53 #undef DIRSIZ
  54 #define DIRSIZ(dp) \
  55     ((sizeof (struct dirent) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))
  56
  57 int
  58 scandir(dirname, namelist, select, dcomp)
  59         const char *dirname;
  60         struct dirent ***namelist;
  61         int (*select) __P((struct dirent *));
  62         int (*dcomp) __P((const void *, const void *));
  63 {
  64         register struct dirent *d, *p, **names;
  65         register size_t nitems;
  66         struct stat stb;
  67         long arraysz;
  68         DIR *dirp;
  69
  70         if ((dirp = opendir(dirname)) == NULL)
  71                 return(-1);
  72         if (fstat(dirp->dd_fd, &stb) < 0)
  73                 return(-1);
  74
  75         /*
  76          * estimate the array size by taking the size of the directory file
  77          * and dividing it by a multiple of the minimum size entry.
  78          */
  79         arraysz = (stb.st_size / 24);
  80         names = (struct dirent **)malloc(arraysz * sizeof(struct dirent *));
  81         if (names == NULL)
  82                 return(-1);
  83
  84         nitems = 0;
  85         while ((d = readdir(dirp)) != NULL) {
  86                 if (select != NULL && !(*select)(d))
  87                         continue;       /* just selected names */
  88                 /*
  89                  * Make a minimum size copy of the data
  90                  */
  91                 p = (struct dirent *)malloc(DIRSIZ(d));
  92                 if (p == NULL)
  93                         return(-1);
  94                 p->d_ino = d->d_ino;
  95                 p->d_reclen = d->d_reclen;
  96                 p->d_namlen = d->d_namlen;
  97                 bcopy(d->d_name, p->d_name, p->d_namlen + 1);
  98                 /*
  99                  * Check to make sure the array has space left and
 100                  * realloc the maximum size.
 101                  */
 102                 if (++nitems >= arraysz) {
 103                         if (fstat(dirp->dd_fd, &stb) < 0)
 104                                 return(-1);     /* just might have grown */
 105                         arraysz = stb.st_size / 12;
 106                         names = (struct dirent **)realloc((char *)names,
 107                                 arraysz * sizeof(struct dirent *));
 108                         if (names == NULL)
 109                                 return(-1);
 110                 }
 111                 names[nitems-1] = p;
 112         }
 113         closedir(dirp);
 114         if (nitems && dcomp != NULL)
 115                 qsort(names, nitems, sizeof(struct dirent *), dcomp);
 116         *namelist = names;
 117         return(nitems);
 118 }
 119
 120 /*
 121  * Alphabetic order comparison routine for those who want it.
 122  */
 123 int
 124 alphasort(d1, d2)
 125         const void *d1;
 126         const void *d2;
 127 {
 128         return(strcmp((*(struct dirent **)d1)->d_name,
 129             (*(struct dirent **)d2)->d_name));
 130 }