freebsd-nq/contrib/less/signal.c
Robert Watson 1ea316270f Currently, less(1) uses K&R prototypes, which both fails to provide useful
compiler-time type checking, and also causes problems for targets where
multiple incompatible calling conventions may be selected based on argument
types.  This change switches less(1) to ANSI prototypes.

While there, we also remove use of "register", and attempt to use "const" a
bit better now that the compiler can check argument types.

Reviewed by:	cem, emaste
MFC after:	3 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D10152
2017-03-31 21:29:43 +00:00

255 lines
4.4 KiB
C

/*
* Copyright (C) 1984-2015 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.
*/
/* $FreeBSD$ */
/*
* 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;
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 less_is_more;
extern long jump_sline_fraction;
/*
* Interrupt signal handler.
*/
/* 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 (less_is_more)
quit(0);
if (reading)
intread(); /* May longjmp */
}
#ifdef SIGTSTP
/*
* "Stop" (^Z) signal handler.
*/
/* ARGSUSED*/
static RETSIGTYPE
stop(int type)
{
LSIGNAL(SIGTSTP, stop);
sigs |= S_STOP;
if (reading)
intread();
}
#endif
#ifdef SIGWINCH
/*
* "Window" change handler
*/
/* ARGSUSED*/
public RETSIGTYPE
winch(int type)
{
LSIGNAL(SIGWINCH, winch);
sigs |= S_WINCH;
if (reading)
intread();
}
#else
#ifdef SIGWIND
/*
* "Window" change handler
*/
/* ARGSUSED*/
public RETSIGTYPE
winch(int type)
{
LSIGNAL(SIGWIND, winch);
sigs |= S_WINCH;
if (reading)
intread();
}
#endif
#endif
#if MSDOS_COMPILER==WIN32C
/*
* Handle CTRL-C and CTRL-BREAK keys.
*/
#include "windows.h"
static BOOL WINAPI
wbreak_handler(DWORD dwCtrlType)
{
switch (dwCtrlType)
{
case CTRL_C_EVENT:
case CTRL_BREAK_EVENT:
sigs |= S_INTERRUPT;
return (TRUE);
default:
break;
}
return (FALSE);
}
#endif
/*
* Set up the signal handlers.
*/
public void
init_signals(int on)
{
if (on)
{
/*
* Set signal handlers.
*/
(void) LSIGNAL(SIGINT, u_interrupt);
#if MSDOS_COMPILER==WIN32C
SetConsoleCtrlHandler(wbreak_handler, TRUE);
#endif
#ifdef SIGTSTP
(void) LSIGNAL(SIGTSTP, stop);
#endif
#ifdef SIGWINCH
(void) LSIGNAL(SIGWINCH, winch);
#endif
#ifdef SIGWIND
(void) LSIGNAL(SIGWIND, winch);
#endif
#ifdef SIGQUIT
(void) LSIGNAL(SIGQUIT, SIG_IGN);
#endif
} else
{
/*
* Restore signals to defaults.
*/
(void) LSIGNAL(SIGINT, SIG_DFL);
#if MSDOS_COMPILER==WIN32C
SetConsoleCtrlHandler(wbreak_handler, FALSE);
#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
}
}
/*
* 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);
}
}