xref: /illumos-gate/usr/src/lib/libc/port/stdio/_flsbuf.c (revision 1a2d662a91cee3bf82f41cd47c7ae6f3825d9db2)
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 weak __flsbuf = _flsbuf
31 
32 #include "lint.h"
33 #include "file64.h"
34 #include <mtlib.h>
35 #include <stdio.h>
36 #include <thread.h>
37 #include <synch.h>
38 #include <unistd.h>
39 #include <sys/types.h>
40 #include "stdiom.h"
41 
42 /*
43  * flush (write) buffer, save ch,
44  * return EOF on failure
45  */
46 int
47 _flsbuf(int ch, FILE *iop)
48 {
49 	Uchar uch;
50 
51 	do {	/* only loop if need to use _wrtchk() on non-_IOFBF */
52 		switch (iop->_flag & (_IOFBF | _IOLBF | _IONBF |
53 		    _IOWRT | _IOEOF)) {
54 		case _IOFBF | _IOWRT:	/* okay to do full-buffered case */
55 			if (iop->_base != 0 && iop->_ptr > iop->_base)
56 				goto flush_putc;	/* skip _wrtchk() */
57 			break;
58 		case _IOLBF | _IOWRT:	/* okay to do line-buffered case */
59 			if (iop->_ptr >= _bufend(iop))
60 				/*
61 				 * which will recursively call
62 				 * __flsbuf via putc because of no room
63 				 * in the buffer for the character
64 				 */
65 				goto flush_putc;
66 			if ((*iop->_ptr++ = (unsigned char)ch) == '\n')
67 				(void) _xflsbuf(iop);
68 			iop->_cnt = 0;
69 			goto out;
70 		case _IONBF | _IOWRT:	/* okay to do no-buffered case */
71 			iop->_cnt = 0;
72 			uch = (unsigned char)ch;
73 			if (_xwrite(iop, (char *)&uch, 1) != 1) {
74 				if (!cancel_active())
75 					iop->_flag |= _IOERR;
76 				return (EOF);
77 			}
78 			goto out;
79 		}
80 		if (_wrtchk(iop) != 0)	/* check, correct permissions */
81 			return (EOF);
82 	} while (iop->_flag & (_IOLBF | _IONBF));
83 flush_putc:
84 	(void) _xflsbuf(iop);
85 	(void) PUTC(ch, iop); /*  recursive call */
86 out:
87 	/* necessary for putc() */
88 	return ((iop->_flag & _IOERR) ? EOF : (unsigned char)ch);
89 }
90