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Diffstat (limited to 'usr.bin/more/signal.c')
| -rw-r--r-- | usr.bin/more/signal.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/usr.bin/more/signal.c b/usr.bin/more/signal.c new file mode 100644 index 0000000..67d7e51 --- /dev/null +++ b/usr.bin/more/signal.c @@ -0,0 +1,220 @@ +/* + * Copyright (c) 1988 Mark Nudleman + * Copyright (c) 1988, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef lint +static char sccsid[] = "@(#)signal.c 8.1 (Berkeley) 6/6/93"; +#endif /* not lint */ + +/* + * 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. + */ +int sigs; + +#ifdef SIGTSTP +#define S_STOP 02 +#endif +#if defined(SIGWINCH) || defined(SIGWIND) +#define S_WINCH 04 +#endif + +extern int sc_width, sc_height; +extern int screen_trashed; +extern int lnloop; +extern int linenums; +extern int scroll; +extern int reading; + +#ifdef SIGTSTP +/* + * "Stop" (^Z) signal handler. + */ +static void +stop() +{ + (void)signal(SIGTSTP, stop); + sigs |= S_STOP; + if (reading) + intread(); +} +#endif + +#ifdef SIGWINCH +/* + * "Window" change handler + */ +void +winch() +{ + (void)signal(SIGWINCH, winch); + sigs |= S_WINCH; + if (reading) + intread(); +} +#else +#ifdef SIGWIND +/* + * "Window" change handler + */ +winch() +{ + (void)signal(SIGWIND, winch); + sigs |= S_WINCH; + if (reading) + intread(); +} +#endif +#endif + +static void +purgeandquit() +{ + + purge(); /* purge buffered output */ + quit(); +} + +/* + * Set up the signal handlers. + */ +init_signals(on) + int on; +{ + if (on) + { + /* + * Set signal handlers. + */ + (void)signal(SIGINT, purgeandquit); +#ifdef SIGTSTP + (void)signal(SIGTSTP, stop); +#endif +#ifdef SIGWINCH + (void)signal(SIGWINCH, winch); +#else +#ifdef SIGWIND + (void)signal(SIGWIND, winch); +#endif +#endif + } else + { + /* + * Restore signals to defaults. + */ + (void)signal(SIGINT, SIG_DFL); +#ifdef SIGTSTP + (void)signal(SIGTSTP, SIG_DFL); +#endif +#ifdef SIGWINCH + (void)signal(SIGWINCH, SIG_IGN); +#endif +#ifdef SIGWIND + (void)signal(SIGWIND, SIG_IGN); +#endif + } +} + +/* + * Process any signals we have received. + * A received signal cause a bit to be set in "sigs". + */ +psignals() +{ + register int tsignals; + + if ((tsignals = sigs) == 0) + return; + sigs = 0; + +#ifdef S_WINCH + if (tsignals & S_WINCH) + { + int old_width, old_height; + /* + * Re-execute get_term() 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) + { + scroll = (sc_height + 1) / 2; + screen_trashed = 1; + } + } +#endif +#ifdef SIGTSTP + if (tsignals & S_STOP) + { + /* + * Clean up the terminal. + */ +#ifdef SIGTTOU + (void)signal(SIGTTOU, SIG_IGN); +#endif + lower_left(); + clear_eol(); + deinit(); + (void)flush(); + raw_mode(0); +#ifdef SIGTTOU + (void)signal(SIGTTOU, SIG_DFL); +#endif + (void)signal(SIGTSTP, SIG_DFL); + (void)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. + */ + (void)signal(SIGTSTP, stop); + raw_mode(1); + init(); + screen_trashed = 1; + } +#endif +} |
