diff options
Diffstat (limited to 'signal.c')
| -rwxr-xr-x | signal.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/signal.c b/signal.c new file mode 100755 index 0000000..7bf5b51 --- /dev/null +++ b/signal.c @@ -0,0 +1,256 @@ +/* + * Copyright (C) 1984-2012 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; + +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 long jump_sline_fraction; + +/* + * Interrupt signal handler. + */ + /* ARGSUSED*/ + static RETSIGTYPE +u_interrupt(type) + 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 (reading) + intread(); /* May longjmp */ +} + +#ifdef SIGTSTP +/* + * "Stop" (^Z) signal handler. + */ + /* ARGSUSED*/ + static RETSIGTYPE +stop(type) + int type; +{ + LSIGNAL(SIGTSTP, stop); + sigs |= S_STOP; + if (reading) + intread(); +} +#endif + +#ifdef SIGWINCH +/* + * "Window" change handler + */ + /* ARGSUSED*/ + public RETSIGTYPE +winch(type) + int type; +{ + LSIGNAL(SIGWINCH, winch); + sigs |= S_WINCH; + if (reading) + intread(); +} +#else +#ifdef SIGWIND +/* + * "Window" change handler + */ + /* ARGSUSED*/ + public RETSIGTYPE +winch(type) + 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(dwCtrlType) + 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(on) + 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() +{ + register 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); + } +} |