gen/scandir.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1983, 1993
  24  *      The Regents of the University of California.  All rights reserved.
  25  *
  26  * Redistribution and use in source and binary forms, with or without
  27  * modification, are permitted provided that the following conditions
  28  * are met:
  29  * 1. Redistributions of source code must retain the above copyright
  30  *    notice, this list of conditions and the following disclaimer.
  31  * 2. Redistributions in binary form must reproduce the above copyright
  32  *    notice, this list of conditions and the following disclaimer in the
  33  *    documentation and/or other materials provided with the distribution.
  34  * 3. All advertising materials mentioning features or use of this software
  35  *    must display the following acknowledgement:
  36  *      This product includes software developed by the University of
  37  *      California, Berkeley and its contributors.
  38  * 4. Neither the name of the University nor the names of its contributors
  39  *    may be used to endorse or promote products derived from this software
  40  *    without specific prior written permission.
  41  *
  42  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  43  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  44  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  45  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  46  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  47  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  48  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  49  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  50  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  51  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  52  * SUCH DAMAGE.
  53  */
  54
  55
  56 /*
  57  * Scan the directory dirname calling select to make a list of selected
  58  * directory entries then sort using qsort and compare routine dcomp.
  59  * Returns the number of entries and a pointer to a list of pointers to
  60  * struct dirent (through namelist). Returns -1 if there were any errors.
  61  */
  62
  63 #include <sys/types.h>
  64 #include <sys/stat.h>
  65 #include <dirent.h>
  66 #include <stdlib.h>
  67 #include <string.h>
  68
  69 /*
  70  * The DIRSIZ macro is the minimum record length which will hold the directory
  71  * entry.  This requires the amount of space in struct dirent without the
  72  * d_name field, plus enough space for the name and a terminating nul byte
  73  * (dp->d_namlen + 1), rounded up to a 4 byte boundary.
  74  */
  75 #undef DIRSIZ
  76 #define DIRSIZ(dp)                                                      \
  77         ((sizeof(struct dirent) - sizeof(dp)->d_name) +                 \
  78             (((dp)->d_namlen + 1 + 3) &~ 3))
  79
  80 int
  81 scandir(dirname, namelist, select, dcomp)
  82         const char *dirname;
  83         struct dirent ***namelist;
  84         int (*select) __P((struct dirent *));
  85         int (*dcomp) __P((const void *, const void *));
  86 {
  87         register struct dirent *d, *p, **names;
  88         register size_t nitems;
  89         struct stat stb;
  90         long arraysz;
  91         DIR *dirp;
  92
  93         if ((dirp = opendir(dirname)) == NULL)
  94                 return(-1);
  95         if (fstat(dirp->dd_fd, &stb) < 0)
  96                 return(-1);
  97
  98         /*
  99          * estimate the array size by taking the size of the directory file
 100          * and dividing it by a multiple of the minimum size entry.
 101          */
 102         arraysz = (stb.st_size / 24);
 103         names = (struct dirent **)malloc(arraysz * sizeof(struct dirent *));
 104         if (names == NULL)
 105                 return(-1);
 106
 107         nitems = 0;
 108         while ((d = readdir(dirp)) != NULL) {
 109                 if (select != NULL && !(*select)(d))
 110                         continue;       /* just selected names */
 111                 /*
 112                  * Make a minimum size copy of the data
 113                  */
 114                 p = (struct dirent *)malloc(DIRSIZ(d));
 115                 if (p == NULL)
 116                         return(-1);
 117                 p->d_ino = d->d_ino;
 118                 p->d_reclen = d->d_reclen;
 119                 p->d_namlen = d->d_namlen;
 120                 bcopy(d->d_name, p->d_name, p->d_namlen + 1);
 121                 /*
 122                  * Check to make sure the array has space left and
 123                  * realloc the maximum size.
 124                  */
 125                 if (++nitems >= arraysz) {
 126                         if (fstat(dirp->dd_fd, &stb) < 0)
 127                                 return(-1);     /* just might have grown */
 128                         arraysz = stb.st_size / 12;
 129                         names = (struct dirent **)realloc((char *)names,
 130                                 arraysz * sizeof(struct dirent *));
 131                         if (names == NULL)
 132                                 return(-1);
 133                 }
 134                 names[nitems-1] = p;
 135         }
 136         closedir(dirp);
 137         if (nitems && dcomp != NULL)
 138                 qsort(names, nitems, sizeof(struct dirent *), dcomp);
 139         *namelist = names;
 140         return(nitems);
 141 }
 142
 143 /*
 144  * Alphabetic order comparison routine for those who want it.
 145  */
 146 int
 147 alphasort(d1, d2)
 148         const void *d1;
 149         const void *d2;
 150 {
 151         return(strcmp((*(struct dirent **)d1)->d_name,
 152             (*(struct dirent **)d2)->d_name));
 153 }