git.zerfleddert.de Git - micropolis/blame_incremental - src/tcl/compat/opendir.c

/*
 * opendir.c --
 *
 *	This file provides dirent-style directory-reading procedures
 *	for V7 Unix systems that don't have such procedures.  The
 *	origin of this code is unclear, but it seems to have come
 *	originally from Larry Wall.
 *
 */

#include <tclint.h>
#include <tclunix.h>

#undef DIRSIZ
#define DIRSIZ(dp) \
    ((sizeof (struct dirent) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))

/*
 * open a directory.
 */
DIR *
opendir(name)
char *name;
{
	register DIR *dirp;
	register int fd;
	char *myname;

	myname = ((*name == '\0') ? "." : name);
	if ((fd = open(myname, 0, 0)) == -1)
		return NULL;
	if ((dirp = (DIR *)ckalloc(sizeof(DIR))) == NULL) {
		close (fd);
		return NULL;
	}
	dirp->dd_fd = fd;
	dirp->dd_loc = 0;
	return dirp;
}

/*
 * read an old style directory entry and present it as a new one
 */
#ifndef pyr
#define	ODIRSIZ	14

struct	olddirect {
	ino_t	od_ino;
	char	od_name[ODIRSIZ];
};
#else	/* a Pyramid in the ATT universe */
#define	ODIRSIZ	248

struct	olddirect {
	long	od_ino;
	short	od_fill1, od_fill2;
	char	od_name[ODIRSIZ];
};
#endif

/*
 * get next entry in a directory.
 */
struct dirent *
readdir(dirp)
register DIR *dirp;
{
	register struct olddirect *dp;
	static struct dirent dir;

	for (;;) {
		if (dirp->dd_loc == 0) {
			dirp->dd_size = read(dirp->dd_fd, dirp->dd_buf,
			    DIRBLKSIZ);
			if (dirp->dd_size <= 0)
				return NULL;
		}
		if (dirp->dd_loc >= dirp->dd_size) {
			dirp->dd_loc = 0;
			continue;
		}
		dp = (struct olddirect *)(dirp->dd_buf + dirp->dd_loc);
		dirp->dd_loc += sizeof(struct olddirect);
		if (dp->od_ino == 0)
			continue;
		dir.d_ino = dp->od_ino;
		strncpy(dir.d_name, dp->od_name, ODIRSIZ);
		dir.d_name[ODIRSIZ] = '\0'; /* insure null termination */
		dir.d_namlen = strlen(dir.d_name);
		dir.d_reclen = DIRSIZ(&dir);
		return (&dir);
	}
}

/*
 * close a directory.
 */
void
closedir(dirp)
register DIR *dirp;
{
	close(dirp->dd_fd);
	dirp->dd_fd = -1;
	dirp->dd_loc = 0;
	ckfree((char *) dirp);
}
Commit	Line	Data
	1	/*
	2	* opendir.c --
	3	*
	4	* This file provides dirent-style directory-reading procedures
	5	* for V7 Unix systems that don't have such procedures. The
	6	* origin of this code is unclear, but it seems to have come
	7	* originally from Larry Wall.
	8	*
	9	*/
	10
	11	#include <tclint.h>
	12	#include <tclunix.h>
	13
	14	#undef DIRSIZ
	15	#define DIRSIZ(dp) \
	16	((sizeof (struct dirent) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))
	17
	18	/*
	19	* open a directory.
	20	*/
	21	DIR *
	22	opendir(name)
	23	char *name;
	24	{
	25	register DIR *dirp;
	26	register int fd;
	27	char *myname;
	28
	29	myname = ((*name == '\0') ? "." : name);
	30	if ((fd = open(myname, 0, 0)) == -1)
	31	return NULL;
	32	if ((dirp = (DIR *)ckalloc(sizeof(DIR))) == NULL) {
	33	close (fd);
	34	return NULL;
	35	}
	36	dirp->dd_fd = fd;
	37	dirp->dd_loc = 0;
	38	return dirp;
	39	}
	40
	41	/*
	42	* read an old style directory entry and present it as a new one
	43	*/
	44	#ifndef pyr
	45	#define ODIRSIZ 14
	46
	47	struct olddirect {
	48	ino_t od_ino;
	49	char od_name[ODIRSIZ];
	50	};
	51	#else /* a Pyramid in the ATT universe */
	52	#define ODIRSIZ 248
	53
	54	struct olddirect {
	55	long od_ino;
	56	short od_fill1, od_fill2;
	57	char od_name[ODIRSIZ];
	58	};
	59	#endif
	60
	61	/*
	62	* get next entry in a directory.
	63	*/
	64	struct dirent *
	65	readdir(dirp)
	66	register DIR *dirp;
	67	{
	68	register struct olddirect *dp;
	69	static struct dirent dir;
	70
	71	for (;;) {
	72	if (dirp->dd_loc == 0) {
	73	dirp->dd_size = read(dirp->dd_fd, dirp->dd_buf,
	74	DIRBLKSIZ);
	75	if (dirp->dd_size <= 0)
	76	return NULL;
	77	}
	78	if (dirp->dd_loc >= dirp->dd_size) {
	79	dirp->dd_loc = 0;
	80	continue;
	81	}
	82	dp = (struct olddirect *)(dirp->dd_buf + dirp->dd_loc);
	83	dirp->dd_loc += sizeof(struct olddirect);
	84	if (dp->od_ino == 0)
	85	continue;
	86	dir.d_ino = dp->od_ino;
	87	strncpy(dir.d_name, dp->od_name, ODIRSIZ);
	88	dir.d_name[ODIRSIZ] = '\0'; /* insure null termination */
	89	dir.d_namlen = strlen(dir.d_name);
	90	dir.d_reclen = DIRSIZ(&dir);
	91	return (&dir);
	92	}
	93	}
	94
	95	/*
	96	* close a directory.
	97	*/
	98	void
	99	closedir(dirp)
	100	register DIR *dirp;
	101	{
	102	close(dirp->dd_fd);
	103	dirp->dd_fd = -1;
	104	dirp->dd_loc = 0;
	105	ckfree((char *) dirp);
	106	}