summaryrefslogtreecommitdiff
path: root/usr.bin/mg/ttyio.c
blob: 31bc386959b679574aa004478042f6f43112dec3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
/*
 * POSIX terminal I/O.
 *
 * The functions in this file
 * negotiate with the operating system for
 * keyboard characters, and write characters to
 * the display in a barely buffered fashion.
 */
#include	"def.h"

#include	<sys/types.h>
#include	<sys/time.h>
#include	<sys/ioctl.h>
#include	<fcntl.h>
#include	<termios.h>
#include	<term.h>

#define NOBUF	512			/* Output buffer size.		*/

#ifndef TCSASOFT
#define TCSASOFT	0
#endif

char	obuf[NOBUF];			/* Output buffer.		*/
int	nobuf;				/* Buffer count.		*/
struct	termios	oldtty;			/* POSIX tty settings.		*/
struct	termios	newtty;
int	nrow;				/* Terminal size, rows.		*/
int	ncol;				/* Terminal size, columns.	*/

/* XXX - move most of these to def.h? */
void ttopen __P((void));
int ttraw __P((void));
void ttclose __P((void));
int ttcooked __P((void));
void ttputc __P((int));
void ttflush __P((void));
int ttgetc __P((void));
void setttysize __P((void));
int typeahead __P((void));
void panic __P((char *));
int ttwait __P((void));

/*
 * This function gets called once, to set up the terminal
 * On systems w/o TCSASOFT we turn off off flow control,
 * which isn't really the right thing to do.
 */
void
ttopen()
{

	if (ttraw() == FALSE)
		panic("aborting due to terminal initialize failure");
}

/*
 * This function sets the terminal to RAW mode, as defined for the current
 * shell.  This is called both by ttopen() above and by spawncli() to
 * get the current terminal settings and then change them to what
 * mg expects.	Thus, tty changes done while spawncli() is in effect
 * will be reflected in mg.
 */
int
ttraw()
{

	if (tcgetattr(0, &oldtty) < 0) {
		ewprintf("ttopen can't get terminal attributes");
		return(FALSE);
	}
	(void)memcpy(&newtty, &oldtty, sizeof(newtty));
	/* Set terminal to 'raw' mode and ignore a 'break' */
	newtty.c_cc[VMIN] = 1;
	newtty.c_cc[VTIME] = 0;
	newtty.c_iflag |= IGNBRK;
	newtty.c_iflag &= ~(BRKINT | PARMRK | INLCR | IGNCR | ICRNL | IXON);
	newtty.c_oflag &= ~OPOST;
	newtty.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);

#if !TCSASOFT
	/*
	 * If we don't have TCSASOFT, force terminal to
	 * 8 bits, no parity.
	 */
	newtty.c_iflag &= ~ISTRIP;
	newtty.c_cflag &= ~(CSIZE | PARENB);
	newtty.c_cflag |= CS8;
#endif
	if (tcsetattr(0, TCSASOFT | TCSADRAIN, &newtty) < 0) {
		ewprintf("ttopen can't tcsetattr");
		return(FALSE);
	}
}

/*
 * This function gets called just before we go back home to the shell.
 * Put all of the terminal parameters back.
 * Under UN*X this just calls ttcooked(), but the ttclose() hook is in
 * because vttidy() in display.c expects it for portability reasons.
 */
void
ttclose()
{

	if (ttcooked() == FALSE)
		panic("");		/* ttcooked() already printf'd */
}

/*
 * This function restores all terminal settings to their default values,
 * in anticipation of exiting or suspending the editor.
 */
int
ttcooked()
{

	ttflush();
	if (tcsetattr(0, TCSASOFT | TCSADRAIN, &oldtty) < 0) {
		ewprintf("ttclose can't tcsetattr");
		return(FALSE);
	}
	return(TRUE);
}

/*
 * Write character to the display.  Characters are buffered up,
 * to make things a little bit more efficient.
 */
void
ttputc(c)
	int c;
{

	if (nobuf >= NOBUF)
		ttflush();
	obuf[nobuf++] = c;
}

/*
 * Flush output.
 */
void
ttflush()
{

	if (nobuf != 0) {
		if (write(1, obuf, nobuf) != nobuf)
			panic("ttflush write failed");
		nobuf = 0;
	}
}

/*
 * Read character from terminal.
 * All 8 bits are returned, so that you can use
 * a multi-national terminal.
 */
int
ttgetc()
{
	char	c;

	while (read(0, &c, 1) != 1)
		;
	return ((int) c);
}

/*
 * Set the tty size.
 * XXX - belongs in tty.c since it uses terminfo vars.
 */
void
setttysize()
{
#ifdef	TIOCGWINSZ
	struct	winsize winsize;

	if (ioctl(0, TIOCGWINSZ, (char *) &winsize) == 0) {
		nrow = winsize.ws_row;
		ncol = winsize.ws_col;
	} else nrow = 0;
#endif
	if ((nrow <= 0 || ncol <= 0) &&
	    ((nrow = lines) <= 0 || (ncol = columns) <= 0)) {
		nrow = 24;
		ncol = 80;
	}

	/* Enforce maximum screen size. */
	if (nrow > NROW)
		nrow = NROW;
	if (ncol > NCOL)
		ncol = NCOL;
}

/*
 * Returns TRUE if there are characters waiting to be read.
 */
int
typeahead()
{
	int	x;

	return((ioctl(0, FIONREAD, (char *) &x) < 0) ? 0 : x);
}

/*
 * panic - just exit, as quickly as we can.
 */
void
panic(s)
	char *s;
{

	(void) fputs("panic: ", stderr);
	(void) fputs(s, stderr);
	(void) fputc('\n', stderr);
	abort();		/* To leave a core image. */
}

#ifndef NO_DPROMPT
/*
 * A program to return TRUE if we wait for 2 seconds without anything
 * happening, else return FALSE.  Cribbed from mod.sources xmodem.
 */
int
ttwait()
{
	fd_set		readfds;
	struct timeval	tmout;

	FD_ZERO(&readfds);   
	FD_SET(0, &readfds);

	tmout.tv_sec = 2;
	tmout.tv_usec = 0;

	if ((select(1, &readfds, NULL, NULL, &tmout)) == 0)
		return (TRUE);
	return (FALSE);
}
#endif /* NO_DPROMPT */