usr/src/lib/libc/gen/seekdir.c

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)seekdir.c	5.3 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

#include <sys/param.h>
#include <sys/dir.h>

/*
 * seek to an entry in a directory.
 * Only values returned by "telldir" should be passed to seekdir.
 */
void
seekdir(dirp, loc)
	register DIR *dirp;
	long loc;
{
	long curloc, base, offset;
	struct direct *dp;
	extern long lseek();

	curloc = telldir(dirp);
	if (loc == curloc)
		return;
	base = loc & ~(DIRBLKSIZ - 1);
	offset = loc & (DIRBLKSIZ - 1);
	(void) lseek(dirp->dd_fd, base, 0);
	dirp->dd_loc = 0;
	while (dirp->dd_loc < offset) {
		dp = readdir(dirp);
		if (dp == NULL)
			return;
	}
}
Commit	Line	Data
	1	/*
	2	* Copyright (c) 1983 Regents of the University of California.
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms are permitted
	6	* provided that the above copyright notice and this paragraph are
	7	* duplicated in all such forms and that any documentation,
	8	* advertising materials, and other materials related to such
	9	* distribution and use acknowledge that the software was developed
	10	* by the University of California, Berkeley. The name of the
	11	* University may not be used to endorse or promote products derived
	12	* from this software without specific prior written permission.
	13	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
	14	* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
	15	* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
	16	*/
	17
	18	#if defined(LIBC_SCCS) && !defined(lint)
	19	static char sccsid[] = "@(#)seekdir.c 5.3 (Berkeley) %G%";
	20	#endif /* LIBC_SCCS and not lint */
	21
	22	#include <sys/param.h>
	23	#include <sys/dir.h>
	24
	25	/*
	26	* seek to an entry in a directory.
	27	* Only values returned by "telldir" should be passed to seekdir.
	28	*/
	29	void
	30	seekdir(dirp, loc)
	31	register DIR *dirp;
	32	long loc;
	33	{
	34	long curloc, base, offset;
	35	struct direct *dp;
	36	extern long lseek();
	37
	38	curloc = telldir(dirp);
	39	if (loc == curloc)
	40	return;
	41	base = loc & ~(DIRBLKSIZ - 1);
	42	offset = loc & (DIRBLKSIZ - 1);
	43	(void) lseek(dirp->dd_fd, base, 0);
	44	dirp->dd_loc = 0;
	45	while (dirp->dd_loc < offset) {
	46	dp = readdir(dirp);
	47	if (dp == NULL)
	48	return;
	49	}
	50	}