xref: /titanic_51/usr/src/lib/libbc/libc/stdio/sys5/fopen.c (revision 5d54f3d8999eac1762fe0a8c7177d20f1f201fae)
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
57c478bd9Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
67c478bd9Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
77c478bd9Sstevel@tonic-gate  * with the License.
87c478bd9Sstevel@tonic-gate  *
97c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
107c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
117c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
127c478bd9Sstevel@tonic-gate  * and limitations under the License.
137c478bd9Sstevel@tonic-gate  *
147c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
157c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
167c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
177c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
187c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
197c478bd9Sstevel@tonic-gate  *
207c478bd9Sstevel@tonic-gate  * CDDL HEADER END
217c478bd9Sstevel@tonic-gate  */
227c478bd9Sstevel@tonic-gate /*      Copyright (c) 1984 AT&T */
237c478bd9Sstevel@tonic-gate /*        All Rights Reserved   */
247c478bd9Sstevel@tonic-gate 
25*5d54f3d8Smuffin #pragma ident	"%Z%%M%	%I%	%E% SMI"
267c478bd9Sstevel@tonic-gate 
277c478bd9Sstevel@tonic-gate /*LINTLIBRARY*/
28*5d54f3d8Smuffin 
297c478bd9Sstevel@tonic-gate #include <stdio.h>
307c478bd9Sstevel@tonic-gate #include <fcntl.h>
317c478bd9Sstevel@tonic-gate 
32*5d54f3d8Smuffin extern FILE	*_findiop();
33*5d54f3d8Smuffin static FILE	*_endopen();
347c478bd9Sstevel@tonic-gate 
357c478bd9Sstevel@tonic-gate FILE *
36*5d54f3d8Smuffin fopen(char *file, char *mode)
377c478bd9Sstevel@tonic-gate {
387c478bd9Sstevel@tonic-gate 	return (_endopen(file, mode, _findiop()));
397c478bd9Sstevel@tonic-gate }
407c478bd9Sstevel@tonic-gate 
417c478bd9Sstevel@tonic-gate FILE *
42*5d54f3d8Smuffin freopen(char *file, char *mode, FILE *iop)
437c478bd9Sstevel@tonic-gate {
447c478bd9Sstevel@tonic-gate 	(void) fclose(iop); /* doesn't matter if this fails */
457c478bd9Sstevel@tonic-gate 	return (_endopen(file, mode, iop));
467c478bd9Sstevel@tonic-gate }
477c478bd9Sstevel@tonic-gate 
487c478bd9Sstevel@tonic-gate static FILE *
49*5d54f3d8Smuffin _endopen(char *file, char *mode, FILE *iop)
507c478bd9Sstevel@tonic-gate {
51*5d54f3d8Smuffin 	int	plus, oflag, fd;
527c478bd9Sstevel@tonic-gate 
537c478bd9Sstevel@tonic-gate 	if (iop == NULL || file == NULL || file[0] == '\0')
547c478bd9Sstevel@tonic-gate 		return (NULL);
557c478bd9Sstevel@tonic-gate 	plus = (mode[1] == '+');
567c478bd9Sstevel@tonic-gate 	switch (mode[0]) {
577c478bd9Sstevel@tonic-gate 	case 'w':
587c478bd9Sstevel@tonic-gate 		oflag = (plus ? O_RDWR : O_WRONLY) | O_TRUNC | O_CREAT;
597c478bd9Sstevel@tonic-gate 		break;
607c478bd9Sstevel@tonic-gate 	case 'a':
617c478bd9Sstevel@tonic-gate 		oflag = (plus ? O_RDWR : O_WRONLY) | O_APPEND | O_CREAT;
627c478bd9Sstevel@tonic-gate 		break;
637c478bd9Sstevel@tonic-gate 	case 'r':
647c478bd9Sstevel@tonic-gate 		oflag = plus ? O_RDWR : O_RDONLY;
657c478bd9Sstevel@tonic-gate 		break;
667c478bd9Sstevel@tonic-gate 	default:
677c478bd9Sstevel@tonic-gate 		return (NULL);
687c478bd9Sstevel@tonic-gate 	}
697c478bd9Sstevel@tonic-gate 	if ((fd = open(file, oflag, 0666)) < 0)
707c478bd9Sstevel@tonic-gate 		return (NULL);
717c478bd9Sstevel@tonic-gate 	iop->_cnt = 0;
727c478bd9Sstevel@tonic-gate 	iop->_file = fd;
737c478bd9Sstevel@tonic-gate 	iop->_flag = plus ? _IORW : (mode[0] == 'r') ? _IOREAD : _IOWRT;
747c478bd9Sstevel@tonic-gate 	if (mode[0] == 'a')   {
757c478bd9Sstevel@tonic-gate 		if (!plus)  {
767c478bd9Sstevel@tonic-gate 			/* if update only mode, move file pointer to the end
777c478bd9Sstevel@tonic-gate 			   of the file */
787c478bd9Sstevel@tonic-gate 			if ((lseek(fd,0L,2)) < 0)  {
797c478bd9Sstevel@tonic-gate 				(void) close(fd);
807c478bd9Sstevel@tonic-gate 				return NULL;
817c478bd9Sstevel@tonic-gate 			}
827c478bd9Sstevel@tonic-gate 		}
837c478bd9Sstevel@tonic-gate 	}
847c478bd9Sstevel@tonic-gate 	iop->_base = iop->_ptr = NULL;
857c478bd9Sstevel@tonic-gate 	iop->_bufsiz = 0;
867c478bd9Sstevel@tonic-gate 	return (iop);
877c478bd9Sstevel@tonic-gate }
88