xref: /titanic_44/usr/src/lib/libc/port/stdio/fseek.c (revision 7257d1b4d25bfac0c802847390e98a464fd787ac)
17c478bd9Sstevel@tonic-gate /*
27c478bd9Sstevel@tonic-gate  * CDDL HEADER START
37c478bd9Sstevel@tonic-gate  *
47c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*7257d1b4Sraf  * Common Development and Distribution License (the "License").
6*7257d1b4Sraf  * You may not use this file except in compliance with the License.
77c478bd9Sstevel@tonic-gate  *
87c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
107c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
117c478bd9Sstevel@tonic-gate  * and limitations under the License.
127c478bd9Sstevel@tonic-gate  *
137c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
147c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
157c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
167c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
177c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bd9Sstevel@tonic-gate  *
197c478bd9Sstevel@tonic-gate  * CDDL HEADER END
207c478bd9Sstevel@tonic-gate  */
21*7257d1b4Sraf 
227c478bd9Sstevel@tonic-gate /*
23*7257d1b4Sraf  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
247c478bd9Sstevel@tonic-gate  * Use is subject to license terms.
257c478bd9Sstevel@tonic-gate  */
267c478bd9Sstevel@tonic-gate 
277c478bd9Sstevel@tonic-gate /*	Copyright (c) 1988 AT&T	*/
287c478bd9Sstevel@tonic-gate /*	  All Rights Reserved  	*/
297c478bd9Sstevel@tonic-gate 
30*7257d1b4Sraf #pragma ident	"%Z%%M%	%I%	%E% SMI"
317c478bd9Sstevel@tonic-gate 
327c478bd9Sstevel@tonic-gate /*
337c478bd9Sstevel@tonic-gate  * Seek for standard library.  Coordinates with buffering.
347c478bd9Sstevel@tonic-gate  */
357c478bd9Sstevel@tonic-gate 
36*7257d1b4Sraf #pragma weak _fseek = fseek
377c478bd9Sstevel@tonic-gate 
38*7257d1b4Sraf #include "lint.h"
397c478bd9Sstevel@tonic-gate #include "file64.h"
407c478bd9Sstevel@tonic-gate #include "mtlib.h"
417c478bd9Sstevel@tonic-gate #include <stdio.h>
427c478bd9Sstevel@tonic-gate #include <errno.h>
437c478bd9Sstevel@tonic-gate #include <thread.h>
447c478bd9Sstevel@tonic-gate #include <synch.h>
457c478bd9Sstevel@tonic-gate #include <unistd.h>
467c478bd9Sstevel@tonic-gate #include <sys/types.h>
477c478bd9Sstevel@tonic-gate #include "stdiom.h"
487c478bd9Sstevel@tonic-gate 
497c478bd9Sstevel@tonic-gate int
fseek(FILE * iop,long offset,int ptrname)507c478bd9Sstevel@tonic-gate fseek(FILE *iop, long offset, int ptrname)
517c478bd9Sstevel@tonic-gate {
527c478bd9Sstevel@tonic-gate 	off_t	p;
537c478bd9Sstevel@tonic-gate 	rmutex_t *lk;
547c478bd9Sstevel@tonic-gate 
557c478bd9Sstevel@tonic-gate 	FLOCKFILE(lk, iop);
567c478bd9Sstevel@tonic-gate 	iop->_flag &= ~_IOEOF;
577c478bd9Sstevel@tonic-gate 
587c478bd9Sstevel@tonic-gate 	if (!(iop->_flag & _IOREAD) && !(iop->_flag & (_IOWRT | _IORW))) {
597c478bd9Sstevel@tonic-gate 		errno = EBADF;
607c478bd9Sstevel@tonic-gate 		FUNLOCKFILE(lk);
617c478bd9Sstevel@tonic-gate 		return (-1);
627c478bd9Sstevel@tonic-gate 	}
637c478bd9Sstevel@tonic-gate 
647c478bd9Sstevel@tonic-gate 	if (iop->_flag & _IOREAD) {
657c478bd9Sstevel@tonic-gate 		if (ptrname == 1 && iop->_base && !(iop->_flag&_IONBF)) {
667c478bd9Sstevel@tonic-gate 			offset -= iop->_cnt;
677c478bd9Sstevel@tonic-gate 		}
687c478bd9Sstevel@tonic-gate 	} else if (iop->_flag & (_IOWRT | _IORW)) {
697c478bd9Sstevel@tonic-gate 		if (_fflush_u(iop) == EOF) {
707c478bd9Sstevel@tonic-gate 			FUNLOCKFILE(lk);
717c478bd9Sstevel@tonic-gate 			return (-1);
727c478bd9Sstevel@tonic-gate 		}
737c478bd9Sstevel@tonic-gate 	}
747c478bd9Sstevel@tonic-gate 	iop->_cnt = 0;
757c478bd9Sstevel@tonic-gate 	iop->_ptr = iop->_base;
767c478bd9Sstevel@tonic-gate 	if (iop->_flag & _IORW) {
777c478bd9Sstevel@tonic-gate 		iop->_flag &= ~(_IOREAD | _IOWRT);
787c478bd9Sstevel@tonic-gate 	}
797c478bd9Sstevel@tonic-gate 	p = lseek(FILENO(iop), (off_t)offset, ptrname);
807c478bd9Sstevel@tonic-gate 	FUNLOCKFILE(lk);
817c478bd9Sstevel@tonic-gate 	return ((p == (off_t)-1) ? -1: 0);
827c478bd9Sstevel@tonic-gate }
83