221 lines
4.9 KiB
C
221 lines
4.9 KiB
C
/*
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* Copyright (c) 1988 Mark Nudleman
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* Copyright (c) 1988, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifndef lint
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static char sccsid[] = "@(#)signal.c 8.1 (Berkeley) 6/6/93";
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#endif /* not lint */
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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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* If we happen to be reading from a file [in iread()] at the time
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* the signal is received, we call intread to interrupt the iread.
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*/
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#include <less.h>
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#include <signal.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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int sigs;
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#ifdef SIGTSTP
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#define S_STOP 02
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#endif
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#if defined(SIGWINCH) || defined(SIGWIND)
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#define S_WINCH 04
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#endif
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extern int sc_width, sc_height;
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extern int screen_trashed;
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extern int lnloop;
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extern int linenums;
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extern int scroll;
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extern int reading;
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#ifdef SIGTSTP
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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()
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{
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(void)signal(SIGTSTP, stop);
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sigs |= S_STOP;
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if (reading)
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intread();
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}
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#endif
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#ifdef SIGWINCH
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/*
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* "Window" change handler
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*/
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void
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winch()
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{
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(void)signal(SIGWINCH, winch);
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sigs |= S_WINCH;
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if (reading)
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intread();
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}
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#else
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#ifdef SIGWIND
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/*
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* "Window" change handler
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*/
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winch()
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{
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(void)signal(SIGWIND, winch);
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sigs |= S_WINCH;
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if (reading)
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intread();
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}
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#endif
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#endif
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static void
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purgeandquit()
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{
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purge(); /* purge buffered output */
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quit();
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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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init_signals(on)
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int on;
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{
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if (on)
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{
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/*
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* Set signal handlers.
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*/
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(void)signal(SIGINT, purgeandquit);
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#ifdef SIGTSTP
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(void)signal(SIGTSTP, stop);
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#endif
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#ifdef SIGWINCH
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(void)signal(SIGWINCH, winch);
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#else
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#ifdef SIGWIND
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(void)signal(SIGWIND, winch);
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#endif
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#endif
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} else
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{
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/*
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* Restore signals to defaults.
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*/
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(void)signal(SIGINT, SIG_DFL);
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#ifdef SIGTSTP
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(void)signal(SIGTSTP, SIG_DFL);
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#endif
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#ifdef SIGWINCH
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(void)signal(SIGWINCH, SIG_IGN);
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#endif
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#ifdef SIGWIND
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(void)signal(SIGWIND, SIG_IGN);
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#endif
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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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psignals()
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{
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register 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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#ifdef S_WINCH
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if (tsignals & S_WINCH)
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{
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int old_width, old_height;
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/*
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* Re-execute get_term() 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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{
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scroll = (sc_height + 1) / 2;
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screen_trashed = 1;
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}
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}
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#endif
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#ifdef SIGTSTP
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if (tsignals & S_STOP)
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{
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/*
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* Clean up the terminal.
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*/
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#ifdef SIGTTOU
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(void)signal(SIGTTOU, SIG_IGN);
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#endif
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lower_left();
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clear_eol();
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deinit();
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(void)flush();
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raw_mode(0);
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#ifdef SIGTTOU
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(void)signal(SIGTTOU, SIG_DFL);
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#endif
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(void)signal(SIGTSTP, SIG_DFL);
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(void)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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(void)signal(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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}
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#endif
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}
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