xref: /titanic_44/usr/src/lib/libcurses/screen/cbreak.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
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 1997 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 /*
31  * University Copyright- Copyright (c) 1982, 1986, 1988
32  * The Regents of the University of California
33  * All Rights Reserved
34  *
35  * University Acknowledgment- Portions of this document are derived from
36  * software developed by the University of California, Berkeley, and its
37  * contributors.
38  */
39 
40 #pragma ident	"%Z%%M%	%I%	%E% SMI"
41 
42 /*LINTLIBRARY*/
43 
44 /*
45  * Routines to deal with setting and resetting modes in the tty driver.
46  * See also setupterm.c in the termlib part.
47  */
48 #include <sys/types.h>
49 #include "curses_inc.h"
50 
51 int
cbreak(void)52 cbreak(void)
53 {
54 	/*
55 	 * This optimization is here because till SVR3.1 curses did not come up
56 	 * in cbreak mode and now it does.  Therefore, most programs when they
57 	 * call cbreak won't pay for it since we'll know we're in the right
58 	 * mode.
59 	 */
60 
61 	if (cur_term->_fl_rawmode != 1) {
62 #ifdef SYSV
63 	/*
64 	 * You might ask why ICRNL has anything to do with cbreak.
65 	 * The problem is that there are function keys that send
66 	 * a carriage return (some hp's).  Curses cannot virtualize
67 	 * these function keys if CR is being mapped to a NL.  Sooo,
68 	 * when we start a program up we unmap those but if you are
69 	 * in nocbreak then we map them back.  The reason for that is that
70 	 * if a getch or getstr is done and you are in nocbreak the tty
71 	 * driver won't return until it sees a new line and since we've
72 	 * turned it off any program that has nl() and nocbreak() would
73 	 * force the user to type a NL.  The problem with the function keys
74 	 * only gets solved if you are in cbreak mode which is OK
75 	 * since program taking action on a function key is probably
76 	 * in cbreak because who would expect someone to press a function
77 	 * key and then return ?????
78 	 */
79 
80 		PROGTTYS.c_iflag &= ~ICRNL;
81 		PROGTTYS.c_lflag &= ~ICANON;
82 		PROGTTYS.c_cc[VMIN] = 1;
83 		PROGTTYS.c_cc[VTIME] = 0;
84 #else
85 		PROGTTY.sg_flags |= (CBREAK | CRMOD);
86 #endif
87 
88 #ifdef DEBUG
89 #ifdef SYSV
90 		if (outf)
91 			fprintf(outf, "cbreak(), file %x, flags %x\n",
92 			    cur_term->Filedes, PROGTTYS.c_lflag);
93 #else
94 		if (outf)
95 			fprintf(outf, "cbreak(), file %x, flags %x\n",
96 			    cur_term->Filedes, PROGTTY.sg_flags);
97 #endif
98 #endif
99 		cur_term->_fl_rawmode = 1;
100 		cur_term->_delay = -1;
101 		(void) reset_prog_mode();
102 #ifdef FIONREAD
103 		cur_term->timeout = 0;
104 #endif /* FIONREAD */
105 	}
106 	return (OK);
107 }
108