toolchain/gcc/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. 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   5.10 (Berkeley) 2/23/91";
  36 #endif /* LIBC_SCCS and not lint */
  37
  38 /*
  39  * Scan the directory dirname calling select to make a list of selected
  40  * directory entries then sort using qsort and compare routine dcomp.
  41  * Returns the number of entries and a pointer to a list of pointers to
  42  * struct dirent (through namelist). Returns -1 if there were any errors.
  43  */
  44
  45 #include <sys/types.h>
  46 #include <sys/stat.h>
  47 #include <dirent.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50
  51 /*
  52  * The DIRSIZ macro gives the minimum record length which will hold
  53  * the directory entry.  This requires the amount of space in struct dirent
  54  * without the d_name field, plus enough space for the name with a terminating
  55  * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
  56  */
  57 #undef DIRSIZ
  58 #define DIRSIZ(dp) \
  59     ((sizeof (struct dirent) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))
  60
  61 int
  62 scandir(dirname, namelist, select, dcomp)
  63         const char *dirname;
  64         struct dirent ***namelist;
  65         int (*select) __P((struct dirent *));
  66         int (*dcomp) __P((const void *, const void *));
  67 {
  68         register struct dirent *d, *p, **names;
  69         register size_t nitems;
  70         struct stat stb;
  71         long arraysz;
  72         DIR *dirp;
  73
  74         if ((dirp = opendir(dirname)) == NULL)
  75                 return(-1);
  76         if (fstat(dirp->dd_fd, &stb) < 0)
  77                 return(-1);
  78
  79         /*
  80          * estimate the array size by taking the size of the directory file
  81          * and dividing it by a multiple of the minimum size entry.
  82          */
  83         arraysz = (stb.st_size / 24);
  84         names = (struct dirent **)malloc(arraysz * sizeof(struct dirent *));
  85         if (names == NULL)
  86                 return(-1);
  87
  88         nitems = 0;
  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(DIRSIZ(d));
  96                 if (p == NULL)
  97                         return(-1);
  98                 p->d_ino = d->d_ino;
  99                 p->d_reclen = d->d_reclen;
 100                 p->d_namlen = d->d_namlen;
 101                 bcopy(d->d_name, p->d_name, p->d_namlen + 1);
 102                 /*
 103                  * Check to make sure the array has space left and
 104                  * realloc the maximum size.
 105                  */
 106                 if (++nitems >= arraysz) {
 107                         if (fstat(dirp->dd_fd, &stb) < 0)
 108                                 return(-1);     /* just might have grown */
 109                         arraysz = stb.st_size / 12;
 110                         names = (struct dirent **)realloc((char *)names,
 111                                 arraysz * sizeof(struct dirent *));
 112                         if (names == NULL)
 113                                 return(-1);
 114                 }
 115                 names[nitems-1] = p;
 116         }
 117         closedir(dirp);
 118         if (nitems && dcomp != NULL)
 119                 qsort(names, nitems, sizeof(struct dirent *), dcomp);
 120         *namelist = names;
 121         return(nitems);
 122 }
 123
 124 /*
 125  * Alphabetic order comparison routine for those who want it.
 126  */
 127 int
 128 alphasort(d1, d2)
 129         const void *d1;
 130         const void *d2;
 131 {
 132         return(strcmp((*(struct dirent **)d1)->d_name,
 133             (*(struct dirent **)d2)->d_name));
 134 }