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/*
* Copyright (C) 1984-2012 Mark Nudelman
* Modified for use with illumos by Garrett D'Amore.
* Copyright 2015 Garrett D'Amore <garrett@damore.org>
*
* 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, see the README file.
*/
/*
* 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().
*/
#include <signal.h>
#include "less.h"
/*
* signals which need to be processed.
*/
volatile sig_atomic_t signal_intr;
volatile sig_atomic_t signal_stop;
volatile sig_atomic_t signal_winch;
extern int sc_width, sc_height;
extern int screen_trashed;
extern int linenums;
extern int wscroll;
extern int quit_on_intr;
extern long jump_sline_fraction;
/*
* Interrupt signal handler.
*/
static void
u_interrupt(int type)
{
signal_intr = 1;
}
/*
* "Stop" (^Z) signal handler.
*/
static void
stop(int type)
{
signal_stop = 1;
}
/*
* "Window" change handler
*/
void
sigwinch(int type)
{
signal_winch = 1;
}
/*
* Set up the signal handlers.
*/
void
init_signals(int on)
{
if (on) {
/*
* Set signal handlers.
*/
(void) lsignal(SIGINT, u_interrupt);
(void) lsignal(SIGTSTP, stop);
(void) lsignal(SIGWINCH, sigwinch);
(void) lsignal(SIGQUIT, SIG_IGN);
} else {
/*
* Restore signals to defaults.
*/
(void) lsignal(SIGINT, SIG_DFL);
(void) lsignal(SIGTSTP, SIG_DFL);
(void) lsignal(SIGWINCH, SIG_IGN);
(void) lsignal(SIGQUIT, SIG_DFL);
}
}
/*
* Process any signals we have received.
*/
void
psignals(void)
{
if (signal_stop) {
signal_stop = 0;
/*
* Clean up the terminal.
*/
lsignal(SIGTTOU, SIG_IGN);
clear_bot();
deinit();
flush(0);
raw_mode(0);
lsignal(SIGTTOU, SIG_DFL);
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;
signal_winch = 1;
}
if (signal_winch) {
signal_winch = 0;
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();
calc_shift_count();
screen_trashed = 1;
}
}
if (signal_intr) {
signal_intr = 0;
ring_bell();
if (quit_on_intr)
quit(QUIT_INTERRUPT);
}
}
/*
* Custom version of signal() that causes syscalls to be interrupted.
*/
void *
lsignal(int s, void (*a)(int))
{
struct sigaction sa, osa;
sa.sa_handler = a;
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0; /* don't restart system calls */
if (sigaction(s, &sa, &osa) != 0)
return (SIG_ERR);
return (osa.sa_handler);
}
int
any_sigs(void)
{
return (signal_intr || signal_stop || signal_winch);
}
int
abort_sigs(void)
{
return (signal_intr || signal_stop);
}
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