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
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
|
/*
* Copyright (C) 1984-2008 Mark Nudelman
*
* You may distribute under the terms of either the GNU General Public
* License or the Less License, as specified in the README file.
*
* For more information about less, or for information on how to
* contact the author, see the README file.
*/
/* $FreeBSD$ */
/*
* Routines dealing with signals.
*
* A signal usually merely causes a bit to be set in the "signals" word.
* At some convenient time, the mainline code checks to see if any
* signals need processing by calling psignal().
* If we happen to be reading from a file [in iread()] at the time
* the signal is received, we call intread to interrupt the iread.
*/
#include "less.h"
#include <signal.h>
/*
* "sigs" contains bits indicating signals which need to be processed.
*/
public int sigs;
extern int sc_width, sc_height;
extern int screen_trashed;
extern int lnloop;
extern int linenums;
extern int wscroll;
extern int reading;
extern int quit_on_intr;
extern int less_is_more;
extern long jump_sline_fraction;
/*
* Interrupt signal handler.
*/
/* ARGSUSED*/
static RETSIGTYPE
u_interrupt(type)
int type;
{
bell();
#if OS2
LSIGNAL(SIGINT, SIG_ACK);
#endif
LSIGNAL(SIGINT, u_interrupt);
sigs |= S_INTERRUPT;
#if MSDOS_COMPILER==DJGPPC
/*
* If a keyboard has been hit, it must be Ctrl-C
* (as opposed to Ctrl-Break), so consume it.
* (Otherwise, Less will beep when it sees Ctrl-C from keyboard.)
*/
if (kbhit())
getkey();
#endif
if (less_is_more)
quit(0);
if (reading)
intread(); /* May longjmp */
}
#ifdef SIGTSTP
/*
* "Stop" (^Z) signal handler.
*/
/* ARGSUSED*/
static RETSIGTYPE
stop(type)
int type;
{
LSIGNAL(SIGTSTP, stop);
sigs |= S_STOP;
if (reading)
intread();
}
#endif
#ifdef SIGWINCH
/*
* "Window" change handler
*/
/* ARGSUSED*/
public RETSIGTYPE
winch(type)
int type;
{
LSIGNAL(SIGWINCH, winch);
sigs |= S_WINCH;
if (reading)
intread();
}
#else
#ifdef SIGWIND
/*
* "Window" change handler
*/
/* ARGSUSED*/
public RETSIGTYPE
winch(type)
int type;
{
LSIGNAL(SIGWIND, winch);
sigs |= S_WINCH;
if (reading)
intread();
}
#endif
#endif
#if MSDOS_COMPILER==WIN32C
/*
* Handle CTRL-C and CTRL-BREAK keys.
*/
#include "windows.h"
static BOOL WINAPI
wbreak_handler(dwCtrlType)
DWORD dwCtrlType;
{
switch (dwCtrlType)
{
case CTRL_C_EVENT:
case CTRL_BREAK_EVENT:
sigs |= S_INTERRUPT;
return (TRUE);
default:
break;
}
return (FALSE);
}
#endif
/*
* Set up the signal handlers.
*/
public void
init_signals(on)
int on;
{
if (on)
{
/*
* Set signal handlers.
*/
(void) LSIGNAL(SIGINT, u_interrupt);
#if MSDOS_COMPILER==WIN32C
SetConsoleCtrlHandler(wbreak_handler, TRUE);
#endif
#ifdef SIGTSTP
(void) LSIGNAL(SIGTSTP, stop);
#endif
#ifdef SIGWINCH
(void) LSIGNAL(SIGWINCH, winch);
#endif
#ifdef SIGWIND
(void) LSIGNAL(SIGWIND, winch);
#endif
#ifdef SIGQUIT
(void) LSIGNAL(SIGQUIT, SIG_IGN);
#endif
} else
{
/*
* Restore signals to defaults.
*/
(void) LSIGNAL(SIGINT, SIG_DFL);
#if MSDOS_COMPILER==WIN32C
SetConsoleCtrlHandler(wbreak_handler, FALSE);
#endif
#ifdef SIGTSTP
(void) LSIGNAL(SIGTSTP, SIG_DFL);
#endif
#ifdef SIGWINCH
(void) LSIGNAL(SIGWINCH, SIG_IGN);
#endif
#ifdef SIGWIND
(void) LSIGNAL(SIGWIND, SIG_IGN);
#endif
#ifdef SIGQUIT
(void) LSIGNAL(SIGQUIT, SIG_DFL);
#endif
}
}
/*
* Process any signals we have received.
* A received signal cause a bit to be set in "sigs".
*/
public void
psignals()
{
register int tsignals;
if ((tsignals = sigs) == 0)
return;
sigs = 0;
#ifdef SIGTSTP
if (tsignals & S_STOP)
{
/*
* Clean up the terminal.
*/
#ifdef SIGTTOU
LSIGNAL(SIGTTOU, SIG_IGN);
#endif
clear_bot();
deinit();
flush();
raw_mode(0);
#ifdef SIGTTOU
LSIGNAL(SIGTTOU, SIG_DFL);
#endif
LSIGNAL(SIGTSTP, SIG_DFL);
kill(getpid(), SIGTSTP);
/*
* ... Bye bye. ...
* Hopefully we'll be back later and resume here...
* Reset the terminal and arrange to repaint the
* screen when we get back to the main command loop.
*/
LSIGNAL(SIGTSTP, stop);
raw_mode(1);
init();
screen_trashed = 1;
tsignals |= S_WINCH;
}
#endif
#ifdef S_WINCH
if (tsignals & S_WINCH)
{
int old_width, old_height;
/*
* Re-execute scrsize() to read the new window size.
*/
old_width = sc_width;
old_height = sc_height;
get_term();
if (sc_width != old_width || sc_height != old_height)
{
wscroll = (sc_height + 1) / 2;
calc_jump_sline();
screen_trashed = 1;
}
}
#endif
if (tsignals & S_INTERRUPT)
{
if (quit_on_intr)
quit(QUIT_OK);
}
}
|
