* Copyright (C) 1984-2023 Mark Nudelman

/* $NetBSD: signal.c,v 1.5 2023/10/06 05:49:49 simonb Exp $ */

/*
* Copyright (C) 1984-2023 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, 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().
* 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;

static RETSIGTYPE u_interrupt __P((int));
static RETSIGTYPE stop __P((int));
#if MSDOS_COMPILER==WIN32C
static BOOL WINAPI wbreak_handler __P((DWORD));
#endif

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 secure;
extern long jump_sline_fraction;

/*
* Interrupt signal handler.
*/
#if MSDOS_COMPILER!=WIN32C
/* ARGSUSED*/
static RETSIGTYPE u_interrupt(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 HILITE_SEARCH
set_filter_pattern(NULL, 0);
#endif
if (reading)
intread(); /* May longjmp */
}
#endif

#ifdef SIGTSTP
/*
* "Stop" (^Z) signal handler.
*/
/* ARGSUSED*/
static RETSIGTYPE stop(int type)
{
LSIGNAL(SIGTSTP, stop);
sigs |= S_STOP;
if (reading)
intread();
}
#endif

#undef SIG_LESSWINDOW
#ifdef SIGWINCH
#define SIG_LESSWINDOW SIGWINCH
#else
#ifdef SIGWIND
#define SIG_LESSWINDOW SIGWIND
#endif
#endif

#ifdef SIG_LESSWINDOW
/*
* "Window" change handler
*/
/* ARGSUSED*/
public RETSIGTYPE winch(int type)
{
LSIGNAL(SIG_LESSWINDOW, winch);
sigs |= S_WINCH;
if (reading)
intread();
}
#endif

#if MSDOS_COMPILER==WIN32C
/*
* Handle CTRL-C and CTRL-BREAK keys.
*/
#define WIN32_LEAN_AND_MEAN
#include <windows.h>

static BOOL WINAPI wbreak_handler(DWORD dwCtrlType)
{
switch (dwCtrlType)
{
case CTRL_C_EVENT:
case CTRL_BREAK_EVENT:
sigs |= S_INTERRUPT;
#if HILITE_SEARCH
set_filter_pattern(NULL, 0);
#endif
return (TRUE);
default:
break;
}
return (FALSE);
}
#endif

static RETSIGTYPE terminate(int type)
{
quit(15);
}

/*
* Set up the signal handlers.
*/
public void init_signals(int on)
{
if (on)
{
/*
* Set signal handlers.
*/
#if MSDOS_COMPILER==WIN32C
SetConsoleCtrlHandler(wbreak_handler, TRUE);
#else
(void) LSIGNAL(SIGINT, u_interrupt);
#endif
#ifdef SIGTSTP
(void) LSIGNAL(SIGTSTP, secure ? SIG_IGN : stop);
#endif
#ifdef SIGWINCH
(void) LSIGNAL(SIGWINCH, winch);
#endif
#ifdef SIGWIND
(void) LSIGNAL(SIGWIND, winch);
#endif
#ifdef SIGQUIT
(void) LSIGNAL(SIGQUIT, SIG_IGN);
#endif
#ifdef SIGTERM
(void) LSIGNAL(SIGTERM, terminate);
#endif
} else
{
/*
* Restore signals to defaults.
*/
#if MSDOS_COMPILER==WIN32C
SetConsoleCtrlHandler(wbreak_handler, FALSE);
#else
(void) LSIGNAL(SIGINT, SIG_DFL);
#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
#ifdef SIGTERM
(void) LSIGNAL(SIGTERM, SIG_DFL);
#endif
}
}

/*
* Process any signals we have received.
* A received signal cause a bit to be set in "sigs".
*/
public void psignals(void)
{
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();
calc_shift_count();
}
screen_trashed = 1;
}
#endif
if (tsignals & S_INTERRUPT)
{
if (quit_on_intr)
quit(QUIT_INTERRUPT);
}
}