xref: /titanic_51/usr/src/lib/libbc/libc/stdio/sys5/filbuf.c (revision dd51520e127b452179a2ce4ea3bd8dee949f9afe)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 1998 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*      Copyright (c) 1984 AT&T */
28 /*        All Rights Reserved   */
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 /*LINTLIBRARY*/
33 #include <stdio.h>
34 #include <unistd.h>
35 
36 extern void	_findbuf();
37 
38 static void	lbfflush(FILE *);
39 
40 int
41 __filbuf(FILE *iop)
42 {
43 	return (_filbuf(iop));
44 }
45 
46 int
47 _filbuf(FILE *iop)
48 {
49 	if ( !(iop->_flag & _IOREAD) )
50 		if (iop->_flag & _IORW)
51 			iop->_flag |= _IOREAD;
52 		else
53 			return(EOF);
54 
55 	if (iop->_flag&_IOSTRG)
56 		return(EOF);
57 
58 	if (iop->_base == NULL)  /* get buffer if we don't have one */
59 		_findbuf(iop);
60 
61 	/* if this device is a terminal (line-buffered) or unbuffered, then */
62 	/* flush buffers of all line-buffered devices currently writing */
63 
64 	if (iop->_flag & (_IOLBF | _IONBF))
65 		_fwalk(lbfflush);
66 
67 	iop->_ptr = iop->_base;
68 	iop->_cnt = read(fileno(iop), (char *)iop->_base,
69 	    (unsigned)((iop->_flag & _IONBF) ? 1 : iop->_bufsiz ));
70 	if (--iop->_cnt >= 0)		/* success */
71 		return (*iop->_ptr++);
72 	if (iop->_cnt != -1)		/* error */
73 		iop->_flag |= _IOERR;
74 	else {				/* end-of-file */
75 		iop->_flag |= _IOEOF;
76 		if (iop->_flag & _IORW)
77 			iop->_flag &= ~_IOREAD;
78 	}
79 	iop->_cnt = 0;
80 	return (EOF);
81 }
82 
83 static void
84 lbfflush(FILE *iop)
85 {
86 	if (iop->_flag & _IOLBF)
87 		(void) fflush(iop);
88 }
89