xref: /illumos-gate/usr/src/lib/libc/port/stdio/_flsbuf.c (revision 4f364e7c)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #pragma weak __flsbuf = _flsbuf
33 
34 #include "lint.h"
35 #include "file64.h"
36 #include <mtlib.h>
37 #include <stdio.h>
38 #include <thread.h>
39 #include <synch.h>
40 #include <unistd.h>
41 #include <sys/types.h>
42 #include "stdiom.h"
43 
44 int
45 _flsbuf(int ch, FILE *iop)	/* flush (write) buffer, save ch, */
46 				/* return EOF on failure */
47 {
48 	Uchar uch;
49 
50 	do	/* only loop if need to use _wrtchk() on non-_IOFBF */
51 	{
52 		switch (iop->_flag & (_IOFBF | _IOLBF | _IONBF |
53 				_IOWRT | _IOEOF))
54 		{
55 		case _IOFBF | _IOWRT:	/* okay to do full-buffered case */
56 			if (iop->_base != 0 && iop->_ptr > iop->_base)
57 				goto flush_putc;	/* skip _wrtchk() */
58 			break;
59 		case _IOLBF | _IOWRT:	/* okay to do line-buffered case */
60 			if (iop->_ptr >= _bufend(iop))
61 				/*
62 				 * which will recursively call
63 				 * __flsbuf via putc because of no room
64 				 * in the buffer for the character
65 				 */
66 				goto flush_putc;
67 			if ((*iop->_ptr++ = (unsigned char)ch) == '\n')
68 				(void) _xflsbuf(iop);
69 			iop->_cnt = 0;
70 			goto out;
71 		case _IONBF | _IOWRT:	/* okay to do no-buffered case */
72 			iop->_cnt = 0;
73 			uch = (unsigned char)ch;
74 			if (write(GET_FD(iop), (char *)&uch, 1) != 1) {
75 				if (!cancel_active())
76 					iop->_flag |= _IOERR;
77 				return (EOF);
78 			}
79 			goto out;
80 		}
81 		if (_wrtchk(iop) != 0)	/* check, correct permissions */
82 			return (EOF);
83 	} while (iop->_flag & (_IOLBF | _IONBF));
84 flush_putc:
85 	(void) _xflsbuf(iop);
86 	(void) PUTC(ch, iop); /*  recursive call */
87 out:
88 	/* necessary for putc() */
89 	return ((iop->_flag & _IOERR) ? EOF : (unsigned char)ch);
90 }
91