ack/lang/cem/libcc.ansi/misc/opendir.c
2018-06-21 22:33:47 +02:00

67 lines
1.4 KiB
C

/*
opendir -- open a directory stream
last edit: 16-Jun-1987 D A Gwyn
*/
#include <errno.h>
#include <stdlib.h>
#include <sys/errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
typedef void* pointer; /* (void *) if you have it */
extern int _open(const char* path, int flags, int mode);
extern int _close(int d);
extern int _fstat(int fd, struct stat* buf);
#ifndef NULL
#define NULL 0
#endif
#ifndef O_RDONLY
#define O_RDONLY 0
#endif
#ifndef S_ISDIR /* macro to test for directory file */
#define S_ISDIR(mode) (((mode)&S_IFMT) == S_IFDIR)
#endif
DIR* opendir(const char* dirname) /* name of directory */
{
register DIR* dirp; /* -> malloc'ed storage */
register int fd; /* file descriptor for read */
struct stat sbuf; /* result of fstat() */
if ((fd = _open(dirname, O_RDONLY, 0)) < 0)
return NULL; /* errno set by open() */
if (_fstat(fd, &sbuf) != 0 || !S_ISDIR(sbuf.st_mode))
{
(void)_close(fd);
errno = ENOTDIR;
return NULL; /* not a directory */
}
if ((dirp = (DIR*)malloc(sizeof(DIR))) == NULL
|| (dirp->dd_buf = (char*)malloc((unsigned)DIRBUF)) == NULL)
{
register int serrno = errno;
/* errno set to ENOMEM by sbrk() */
if (dirp != NULL)
free((pointer)dirp);
(void)_close(fd);
errno = serrno;
return NULL; /* not enough memory */
}
dirp->dd_fd = fd;
dirp->dd_loc = dirp->dd_size = 0; /* refill needed */
return dirp;
}