minix/commands/ash/dirent.c
2005-04-21 14:53:53 +00:00

194 lines
4.8 KiB
C
Executable file

/*-
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Kenneth Almquist.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char sccsid[] = "@(#)dirent.c 5.1 (Berkeley) 3/7/91";
#endif /* not lint */
#include "shell.h" /* definitions for pointer, NULL, DIRENT, and BSD */
#if ! DIRENT
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#ifndef S_ISDIR /* macro to test for directory file */
#define S_ISDIR(mode) (((mode) & S_IFMT) == S_IFDIR)
#endif
#ifdef BSD
#ifdef __STDC__
int stat(char *, struct stat *);
#else
int stat();
#endif
/*
* The BSD opendir routine doesn't check that what is being opened is a
* directory, so we have to include the check in a wrapper routine.
*/
#undef opendir
DIR *
myopendir(dirname)
char *dirname; /* name of directory */
{
struct stat statb;
if (stat(dirname, &statb) != 0 || ! S_ISDIR(statb.st_mode)) {
errno = ENOTDIR;
return NULL; /* not a directory */
}
return opendir(dirname);
}
#else /* not BSD */
/*
* Dirent routines for old style file systems.
*/
#ifdef __STDC__
pointer malloc(unsigned);
void free(pointer);
int open(char *, int, ...);
int close(int);
int fstat(int, struct stat *);
#else
pointer malloc();
void free();
int open();
int close();
int fstat();
#endif
DIR *
opendir(dirname)
char *dirname; /* name of directory */
{
register DIR *dirp; /* -> malloc'ed storage */
register int fd; /* file descriptor for read */
struct stat statb; /* result of fstat() */
#ifdef O_NDELAY
fd = open(dirname, O_RDONLY|O_NDELAY);
#else
fd = open(dirname, O_RDONLY);
#endif
if (fd < 0)
return NULL; /* errno set by open() */
if (fstat(fd, &statb) != 0 || !S_ISDIR(statb.st_mode)) {
(void)close(fd);
errno = ENOTDIR;
return NULL; /* not a directory */
}
if ((dirp = (DIR *)malloc(sizeof(DIR))) == NULL) {
(void)close(fd);
errno = ENOMEM;
return NULL; /* not enough memory */
}
dirp->dd_fd = fd;
dirp->dd_nleft = 0; /* refill needed */
return dirp;
}
int
closedir(dirp)
register DIR *dirp; /* stream from opendir() */
{
register int fd;
if (dirp == NULL) {
errno = EFAULT;
return -1; /* invalid pointer */
}
fd = dirp->dd_fd;
free((pointer)dirp);
return close(fd);
}
struct dirent *
readdir(dirp)
register DIR *dirp; /* stream from opendir() */
{
register struct direct *dp;
register char *p, *q;
register int i;
do {
if ((dirp->dd_nleft -= sizeof (struct direct)) < 0) {
if ((i = read(dirp->dd_fd,
(char *)dirp->dd_buf,
DIRBUFENT*sizeof(struct direct))) <= 0) {
if (i == 0)
errno = 0; /* unnecessary */
return NULL; /* EOF or error */
}
dirp->dd_loc = dirp->dd_buf;
dirp->dd_nleft = i - sizeof (struct direct);
}
dp = dirp->dd_loc++;
} while (dp->d_ino == 0);
dirp->dd_entry.d_ino = dp->d_ino;
/* now copy the name, nul terminating it */
p = dp->d_name;
q = dirp->dd_entry.d_name;
i = DIRSIZ;
while (--i >= 0 && *p != '\0')
*q++ = *p++;
*q = '\0';
return &dirp->dd_entry;
}
#endif /* BSD */
#endif /* DIRENT */