opendir.c

操作系统SunOS 4.1.3版本的源码

#if !defined(lint) && defined(SCCSIDS)
static	char sccsid[] = "@(#)opendir.c 1.1 92/07/30 SMI";
#endif

#include <sys/param.h>
#include <sys/stat.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>

/*
 * open a directory.
 */
DIR *
opendir(name)
	char *name;
{
	register DIR *dirp;
	register int fd;
	struct stat sb;
	extern int errno;
	extern char *malloc();
	extern int open(), close(), fstat();

	if ((fd = open(name, 0)) == -1)
		return (NULL);
	if (fstat(fd, &sb) == -1) {
		(void) close(fd);
		return (NULL);
	}
	if ((sb.st_mode & S_IFMT) != S_IFDIR) {
		errno = ENOTDIR;
		(void) close(fd);
		return (NULL);
	}
	if (((dirp = (DIR *)malloc(sizeof(DIR))) == NULL) ||
	    ((dirp->dd_buf = malloc(sb.st_blksize)) == NULL)) {
		if (dirp)
			free(dirp);
		(void) close(fd);
		return (NULL);
	}
	dirp->dd_fd = fd;
	dirp->dd_loc = 0;
	dirp->dd_size = 0;
	dirp->dd_bsize = sb.st_blksize;
	dirp->dd_off = 0;
	(void) fcntl(fd, F_SETFD, FD_CLOEXEC);
	return (dirp);
}