macro and text revision (-mdoc version 3)

[unix-history] / usr / src / lib / libc / gen / opendir.c

/*
* Copyright (c) 1983 Regents of the University of California.
* All rights reserved.
*
* %sccs.include.redist.c%
*/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)opendir.c   5.11 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

#include <sys/param.h>
#include <dirent.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>

long _rewinddir;

/*
* open a directory.
*/
DIR *
opendir(name)
       const char *name;
{
       register DIR *dirp;
       register int fd;

       if ((fd = open(name, 0)) == -1)
               return NULL;
       if (fcntl(fd, F_SETFD, 1) == -1 ||
           (dirp = (DIR *)malloc(sizeof(DIR))) == NULL) {
               close (fd);
               return NULL;
       }
       /*
        * If CLSIZE is an exact multiple of DIRBLKSIZ, use a CLSIZE
        * buffer that it cluster boundary aligned.
        * Hopefully this can be a big win someday by allowing page trades
        * to user space to be done by getdirentries()
        */
       if ((CLSIZE % DIRBLKSIZ) == 0) {
               dirp->dd_buf = malloc(CLSIZE);
               dirp->dd_len = CLSIZE;
       } else {
               dirp->dd_buf = malloc(DIRBLKSIZ);
               dirp->dd_len = DIRBLKSIZ;
       }
       if (dirp->dd_buf == NULL) {
               close (fd);
               return NULL;
       }
       dirp->dd_fd = fd;
       dirp->dd_loc = 0;
       dirp->dd_seek = 0;
       /*
        * Set up seek point for rewinddir.
        */
       _rewinddir = telldir(dirp);
       return dirp;
}