Mercurial > octave
view info/signals.c @ 1227:766e2a1a4e7b
[project @ 1995-04-10 00:48:19 by jwe]
author | jwe |
---|---|
date | Mon, 10 Apr 1995 00:50:03 +0000 |
parents | 6a2e35dc94c3 |
children | 5fb4ee02da70 |
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/* signals.c -- Install and maintain Info signal handlers. */ /* This file is part of GNU Info, a program for reading online documentation stored in Info format. Copyright (C) 1993 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. Written by Brian Fox (bfox@ai.mit.edu). */ #include "info.h" #include "signals.h" /* **************************************************************** */ /* */ /* Pretending That We Have POSIX Signals */ /* */ /* **************************************************************** */ #if !defined (_POSIX_VERSION) /* Perform OPERATION on NEWSET, perhaps leaving information in OLDSET. */ static void sigprocmask (operation, newset, oldset) int operation, *newset, *oldset; { switch (operation) { case SIG_UNBLOCK: #if defined (HAVE_SIGSETMASK) sigsetmask (sigblock (0) & ~(*newset)); #endif /* HAVE_SIGSETMASK */ break; case SIG_BLOCK: *oldset = sigblock (*newset); break; case SIG_SETMASK: #if defined (HAVE_SIGSETMASK) sigsetmask (*newset); #endif /* HAVE_SIGSETMASK */ break; default: abort (); } } #endif /* !_POSIX_VERSION */ /* **************************************************************** */ /* */ /* Signal Handling for Info */ /* */ /* **************************************************************** */ typedef void SigHandlerType; typedef SigHandlerType SigHandler (); static SigHandlerType info_signal_handler (); static SigHandler *old_TSTP, *old_TTOU, *old_TTIN; static SigHandler *old_WINCH, *old_INT; void initialize_info_signal_handler () { #if defined (SIGTSTP) old_TSTP = (SigHandler *) signal (SIGTSTP, info_signal_handler); old_TTOU = (SigHandler *) signal (SIGTTOU, info_signal_handler); old_TTIN = (SigHandler *) signal (SIGTTIN, info_signal_handler); #endif /* SIGTSTP */ #if defined (SIGWINCH) old_WINCH = (SigHandler *) signal (SIGWINCH, info_signal_handler); #endif #if defined (SIGINT) old_INT = (SigHandler *) signal (SIGINT, info_signal_handler); #endif } void clear_info_signal_handler () { #if defined (SIGTSTP) signal (SIGTSTP, old_TSTP); signal (SIGTTOU, old_TTOU); signal (SIGTTIN, old_TTIN); #endif /* SIGTSTP */ #if defined (SIGWINCH) signal (SIGWINCH, old_WINCH); #endif #if defined (SIGINT) signal (SIGINT, old_INT); #endif } static void redisplay_after_signal () { terminal_clear_screen (); display_clear_display (the_display); window_mark_chain (windows, W_UpdateWindow); display_update_display (windows); display_cursor_at_point (active_window); fflush (stdout); } static SigHandlerType info_signal_handler (sig) int sig; { SigHandler **old_signal_handler; switch (sig) { #if defined (SIGTSTP) case SIGTSTP: case SIGTTOU: case SIGTTIN: #endif #if defined (SIGINT) case SIGINT: #endif { #if defined (SIGTSTP) if (sig == SIGTSTP) old_signal_handler = &old_TSTP; else if (sig == SIGTTOU) old_signal_handler = &old_TTOU; else if (sig == SIGTTIN) old_signal_handler = &old_TTIN; #endif /* SIGTSTP */ #if defined (SIGINT) else if (sig == SIGINT) old_signal_handler = &old_INT; #endif /* For stop signals, restore the terminal IO, leave the cursor at the bottom of the window, and stop us. */ terminal_goto_xy (0, screenheight - 1); terminal_clear_to_eol (); fflush (stdout); terminal_unprep_terminal (); UNBLOCK_SIGNAL (sig); signal (sig, *old_signal_handler); kill (getpid (), sig); /* The program is returning now. Restore our signal handler, turn on terminal handling, redraw the screen, and place the cursor where it belongs. */ terminal_prep_terminal (); *old_signal_handler = (SigHandler *) signal (sig, info_signal_handler); redisplay_after_signal (); fflush (stdout); } break; #if defined (SIGWINCH) case SIGWINCH: { /* Turn off terminal IO, tell our parent that the window has changed, then reinitialize the terminal and rebuild our windows. */ old_signal_handler = &old_WINCH; terminal_goto_xy (0, 0); fflush (stdout); terminal_unprep_terminal (); signal (sig, *old_signal_handler); UNBLOCK_SIGNAL (sig); kill (getpid (), sig); /* After our old signal handler returns... */ terminal_get_screen_size (); terminal_prep_terminal (); display_initialize_display (screenwidth, screenheight); window_new_screen_size (screenwidth, screenheight, (VFunction *)NULL); *old_signal_handler = (SigHandler *) signal (sig, info_signal_handler); redisplay_after_signal (); } break; #endif /* SIGWINCH */ } }