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2ec5f51d NW |
1 | /* |
2 | * Copyright (c) 1988 Mark Nudleman | |
3 | * Copyright (c) 1988 Regents of the University of California. | |
4 | * All rights reserved. | |
5 | * | |
6 | * Redistribution and use in source and binary forms, with or without | |
7 | * modification, are permitted provided that the following conditions | |
8 | * are met: | |
9 | * 1. Redistributions of source code must retain the above copyright | |
10 | * notice, this list of conditions and the following disclaimer. | |
11 | * 2. Redistributions in binary form must reproduce the above copyright | |
12 | * notice, this list of conditions and the following disclaimer in the | |
13 | * documentation and/or other materials provided with the distribution. | |
14 | * 3. All advertising materials mentioning features or use of this software | |
15 | * must display the following acknowledgement: | |
16 | * This product includes software developed by the University of | |
17 | * California, Berkeley and its contributors. | |
18 | * 4. Neither the name of the University nor the names of its contributors | |
19 | * may be used to endorse or promote products derived from this software | |
20 | * without specific prior written permission. | |
21 | * | |
22 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
23 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
24 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
25 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
26 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
27 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
28 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
29 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
30 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
31 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
32 | * SUCH DAMAGE. | |
33 | */ | |
34 | ||
35 | #ifndef lint | |
36 | static char sccsid[] = "@(#)signal.c 5.8 (Berkeley) 3/1/91"; | |
37 | #endif /* not lint */ | |
38 | ||
39 | /* | |
40 | * Routines dealing with signals. | |
41 | * | |
42 | * A signal usually merely causes a bit to be set in the "signals" word. | |
43 | * At some convenient time, the mainline code checks to see if any | |
44 | * signals need processing by calling psignal(). | |
45 | * If we happen to be reading from a file [in iread()] at the time | |
46 | * the signal is received, we call intread to interrupt the iread. | |
47 | */ | |
48 | ||
49 | #include <less.h> | |
50 | #include <signal.h> | |
51 | ||
52 | /* | |
53 | * "sigs" contains bits indicating signals which need to be processed. | |
54 | */ | |
55 | int sigs; | |
56 | ||
57 | #ifdef SIGTSTP | |
58 | #define S_STOP 02 | |
59 | #endif | |
60 | #if defined(SIGWINCH) || defined(SIGWIND) | |
61 | #define S_WINCH 04 | |
62 | #endif | |
63 | ||
64 | extern int sc_width, sc_height; | |
65 | extern int screen_trashed; | |
66 | extern int lnloop; | |
67 | extern int linenums; | |
68 | extern int scroll; | |
69 | extern int reading; | |
70 | ||
71 | #ifdef SIGTSTP | |
72 | /* | |
73 | * "Stop" (^Z) signal handler. | |
74 | */ | |
75 | static void | |
76 | stop() | |
77 | { | |
78 | (void)signal(SIGTSTP, stop); | |
79 | sigs |= S_STOP; | |
80 | if (reading) | |
81 | intread(); | |
82 | } | |
83 | #endif | |
84 | ||
85 | #ifdef SIGWINCH | |
86 | /* | |
87 | * "Window" change handler | |
88 | */ | |
89 | void | |
90 | winch() | |
91 | { | |
92 | (void)signal(SIGWINCH, winch); | |
93 | sigs |= S_WINCH; | |
94 | if (reading) | |
95 | intread(); | |
96 | } | |
97 | #else | |
98 | #ifdef SIGWIND | |
99 | /* | |
100 | * "Window" change handler | |
101 | */ | |
102 | winch() | |
103 | { | |
104 | (void)signal(SIGWIND, winch); | |
105 | sigs |= S_WINCH; | |
106 | if (reading) | |
107 | intread(); | |
108 | } | |
109 | #endif | |
110 | #endif | |
111 | ||
112 | static void | |
113 | purgeandquit() | |
114 | { | |
115 | ||
116 | purge(); /* purge buffered output */ | |
117 | quit(); | |
118 | } | |
119 | ||
120 | /* | |
121 | * Set up the signal handlers. | |
122 | */ | |
123 | init_signals(on) | |
124 | int on; | |
125 | { | |
126 | if (on) | |
127 | { | |
128 | /* | |
129 | * Set signal handlers. | |
130 | */ | |
131 | (void)signal(SIGINT, purgeandquit); | |
132 | #ifdef SIGTSTP | |
133 | (void)signal(SIGTSTP, stop); | |
134 | #endif | |
135 | #ifdef SIGWINCH | |
136 | (void)signal(SIGWINCH, winch); | |
137 | #else | |
138 | #ifdef SIGWIND | |
139 | (void)signal(SIGWIND, winch); | |
140 | #endif | |
141 | #endif | |
142 | } else | |
143 | { | |
144 | /* | |
145 | * Restore signals to defaults. | |
146 | */ | |
147 | (void)signal(SIGINT, SIG_DFL); | |
148 | #ifdef SIGTSTP | |
149 | (void)signal(SIGTSTP, SIG_DFL); | |
150 | #endif | |
151 | #ifdef SIGWINCH | |
152 | (void)signal(SIGWINCH, SIG_IGN); | |
153 | #endif | |
154 | #ifdef SIGWIND | |
155 | (void)signal(SIGWIND, SIG_IGN); | |
156 | #endif | |
157 | } | |
158 | } | |
159 | ||
160 | /* | |
161 | * Process any signals we have received. | |
162 | * A received signal cause a bit to be set in "sigs". | |
163 | */ | |
164 | psignals() | |
165 | { | |
166 | register int tsignals; | |
167 | ||
168 | if ((tsignals = sigs) == 0) | |
169 | return; | |
170 | sigs = 0; | |
171 | ||
172 | #ifdef S_WINCH | |
173 | if (tsignals & S_WINCH) | |
174 | { | |
175 | int old_width, old_height; | |
176 | /* | |
177 | * Re-execute get_term() to read the new window size. | |
178 | */ | |
179 | old_width = sc_width; | |
180 | old_height = sc_height; | |
181 | get_term(); | |
182 | if (sc_width != old_width || sc_height != old_height) | |
183 | { | |
184 | scroll = (sc_height + 1) / 2; | |
185 | screen_trashed = 1; | |
186 | } | |
187 | } | |
188 | #endif | |
189 | #ifdef SIGTSTP | |
190 | if (tsignals & S_STOP) | |
191 | { | |
192 | /* | |
193 | * Clean up the terminal. | |
194 | */ | |
195 | #ifdef SIGTTOU | |
196 | (void)signal(SIGTTOU, SIG_IGN); | |
197 | #endif | |
198 | lower_left(); | |
199 | clear_eol(); | |
200 | deinit(); | |
201 | (void)flush(); | |
202 | raw_mode(0); | |
203 | #ifdef SIGTTOU | |
204 | (void)signal(SIGTTOU, SIG_DFL); | |
205 | #endif | |
206 | (void)signal(SIGTSTP, SIG_DFL); | |
207 | (void)kill(getpid(), SIGTSTP); | |
208 | /* | |
209 | * ... Bye bye. ... | |
210 | * Hopefully we'll be back later and resume here... | |
211 | * Reset the terminal and arrange to repaint the | |
212 | * screen when we get back to the main command loop. | |
213 | */ | |
214 | (void)signal(SIGTSTP, stop); | |
215 | raw_mode(1); | |
216 | init(); | |
217 | screen_trashed = 1; | |
218 | } | |
219 | #endif | |
220 | } |