xref: /illumos-gate/usr/src/lib/libcurses/screen/cbreak.c (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
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 /*LINTLIBRARY*/
41 
42 /*
43  * Routines to deal with setting and resetting modes in the tty driver.
44  * See also setupterm.c in the termlib part.
45  */
46 #include <sys/types.h>
47 #include "curses_inc.h"
48 
49 int
50 cbreak(void)
51 {
52 	/*
53 	 * This optimization is here because till SVR3.1 curses did not come up
54 	 * in cbreak mode and now it does.  Therefore, most programs when they
55 	 * call cbreak won't pay for it since we'll know we're in the right
56 	 * mode.
57 	 */
58 
59 	if (cur_term->_fl_rawmode != 1) {
60 #ifdef SYSV
61 	/*
62 	 * You might ask why ICRNL has anything to do with cbreak.
63 	 * The problem is that there are function keys that send
64 	 * a carriage return (some hp's).  Curses cannot virtualize
65 	 * these function keys if CR is being mapped to a NL.  Sooo,
66 	 * when we start a program up we unmap those but if you are
67 	 * in nocbreak then we map them back.  The reason for that is that
68 	 * if a getch or getstr is done and you are in nocbreak the tty
69 	 * driver won't return until it sees a new line and since we've
70 	 * turned it off any program that has nl() and nocbreak() would
71 	 * force the user to type a NL.  The problem with the function keys
72 	 * only gets solved if you are in cbreak mode which is OK
73 	 * since program taking action on a function key is probably
74 	 * in cbreak because who would expect someone to press a function
75 	 * key and then return ?????
76 	 */
77 
78 		PROGTTYS.c_iflag &= ~ICRNL;
79 		PROGTTYS.c_lflag &= ~ICANON;
80 		PROGTTYS.c_cc[VMIN] = 1;
81 		PROGTTYS.c_cc[VTIME] = 0;
82 #else
83 		PROGTTY.sg_flags |= (CBREAK | CRMOD);
84 #endif
85 
86 #ifdef DEBUG
87 #ifdef SYSV
88 		if (outf)
89 			fprintf(outf, "cbreak(), file %x, flags %x\n",
90 			    cur_term->Filedes, PROGTTYS.c_lflag);
91 #else
92 		if (outf)
93 			fprintf(outf, "cbreak(), file %x, flags %x\n",
94 			    cur_term->Filedes, PROGTTY.sg_flags);
95 #endif
96 #endif
97 		cur_term->_fl_rawmode = 1;
98 		cur_term->_delay = -1;
99 		(void) reset_prog_mode();
100 #ifdef FIONREAD
101 		cur_term->timeout = 0;
102 #endif /* FIONREAD */
103 	}
104 	return (OK);
105 }
106