ack/lang/cem/libcc.ansi/misc/opendir.c

68 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;
}