glibc/sysdeps/unix/readdir.c
1995-02-18 01:27:10 +00:00

83 lines
2.3 KiB
C

/* Copyright (C) 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <errno.h>
#include <limits.h>
#include <stddef.h>
#include <string.h>
#include <dirent.h>
#include <unistd.h>
#include <sys/types.h>
#include "direct.h" /* This file defines `struct direct'. */
/* direct.h may have an alternate definition for this. */
#ifndef D_RECLEN
#define D_RECLEN(dp) ((dp)->d_reclen)
#endif
/* Read a directory entry from DIRP. */
struct dirent *
DEFUN(readdir, (dirp), DIR *dirp)
{
if (dirp == NULL || dirp->__data == NULL)
{
errno = EINVAL;
return NULL;
}
while (1)
{
struct direct *dp;
if (dirp->__offset >= dirp->__size)
{
/* We've emptied out our buffer. Refill it. */
off_t base;
ssize_t bytes = __getdirentries (dirp->__fd, dirp->__data,
dirp->__allocation, &base);
if (bytes <= 0)
return NULL;
dirp->__size = (size_t) bytes;
/* Reset the offset into the buffer. */
dirp->__offset = 0;
}
dp = (struct direct *) &dirp->__data[dirp->__offset];
dirp->__offset += D_RECLEN (dp);
if (dp->d_ino != 0)
{
/* Not a deleted file. */
register struct dirent *d = &dirp->__entry;
register const char *p;
d->d_fileno = (ino_t) dp->d_ino;
/* On some systems the name length does not actually mean much.
But we always use it as a maximum. */
p = memchr ((PTR) dp->d_name, '\0', D_NAMLEN (dp) + 1);
d->d_namlen = (p != NULL) ? p - dp->d_name : D_NAMLEN (dp);
memcpy (d->d_name, dp->d_name, d->d_namlen + 1);
return d;
}
}
}