GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.bin/less/less/../signal.c Lines: 14 52 26.9 %
Date: 2017-11-13 Branches: 2 18 11.1 %

Line Branch Exec Source
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/*
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 * Copyright (C) 1984-2012  Mark Nudelman
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 * Modified for use with illumos by Garrett D'Amore.
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 * Copyright 2015 Garrett D'Amore <garrett@damore.org>
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 *
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 * You may distribute under the terms of either the GNU General Public
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 * License or the Less License, as specified in the README file.
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 *
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 * For more information, see the README file.
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 */
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/*
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 * Routines dealing with signals.
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 *
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 * A signal usually merely causes a bit to be set in the "signals" word.
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 * At some convenient time, the mainline code checks to see if any
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 * signals need processing by calling psignal().
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 */
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#include <signal.h>
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#include "less.h"
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/*
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 * "sigs" contains bits indicating signals which need to be processed.
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 */
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volatile sig_atomic_t sigs;
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extern int sc_width, sc_height;
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extern int screen_trashed;
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extern int linenums;
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extern int wscroll;
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extern int quit_on_intr;
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extern long jump_sline_fraction;
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/*
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 * Interrupt signal handler.
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 */
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static void
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u_interrupt(int type)
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{
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	sigs |= S_INTERRUPT;
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}
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/*
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 * "Stop" (^Z) signal handler.
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 */
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static void
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stop(int type)
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{
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	sigs |= S_STOP;
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}
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/*
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 * "Window" change handler
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 */
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void
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sigwinch(int type)
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{
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	sigs |= S_WINCH;
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}
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/*
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 * Set up the signal handlers.
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 */
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void
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init_signals(int on)
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{
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	if (on) {
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		/*
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		 * Set signal handlers.
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		 */
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		(void) lsignal(SIGINT, u_interrupt);
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		(void) lsignal(SIGTSTP, stop);
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		(void) lsignal(SIGWINCH, sigwinch);
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		(void) lsignal(SIGQUIT, SIG_IGN);
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	} else {
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		/*
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		 * Restore signals to defaults.
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		 */
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		(void) lsignal(SIGINT, SIG_DFL);
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		(void) lsignal(SIGTSTP, SIG_DFL);
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		(void) lsignal(SIGWINCH, SIG_IGN);
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		(void) lsignal(SIGQUIT, SIG_DFL);
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	}
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}
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/*
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 * Process any signals we have received.
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 * A received signal cause a bit to be set in "sigs".
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 */
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void
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psignals(void)
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{
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	int tsignals;
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	if ((tsignals = sigs) == 0)
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		return;
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	sigs = 0;
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	if (tsignals & S_STOP) {
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		/*
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		 * Clean up the terminal.
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		 */
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		lsignal(SIGTTOU, SIG_IGN);
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		clear_bot();
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		deinit();
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		flush(0);
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		raw_mode(0);
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		lsignal(SIGTTOU, SIG_DFL);
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		lsignal(SIGTSTP, SIG_DFL);
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		kill(getpid(), SIGTSTP);
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		/*
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		 * ... Bye bye. ...
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		 * Hopefully we'll be back later and resume here...
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		 * Reset the terminal and arrange to repaint the
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		 * screen when we get back to the main command loop.
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		 */
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		lsignal(SIGTSTP, stop);
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		raw_mode(1);
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		init();
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		screen_trashed = 1;
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		tsignals |= S_WINCH;
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	}
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	if (tsignals & S_WINCH) {
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		int old_width, old_height;
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		/*
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		 * Re-execute scrsize() to read the new window size.
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		 */
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		old_width = sc_width;
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		old_height = sc_height;
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		get_term();
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		if (sc_width != old_width || sc_height != old_height) {
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			wscroll = (sc_height + 1) / 2;
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			calc_jump_sline();
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			calc_shift_count();
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			screen_trashed = 1;
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		}
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	}
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	if (tsignals & S_INTERRUPT) {
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		ring_bell();
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		if (quit_on_intr)
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			quit(QUIT_INTERRUPT);
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	}
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}
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/*
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 * Custom version of signal() that causes syscalls to be interrupted.
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 */
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void *
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lsignal(int s, void (*a)(int))
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{
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	struct sigaction sa, osa;
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	sa.sa_handler = a;
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	sigemptyset(&sa.sa_mask);
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	sa.sa_flags = 0;		/* don't restart system calls */
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	if (sigaction(s, &sa, &osa) != 0)
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		return (SIG_ERR);
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	return (osa.sa_handler);
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}