signal(3tcl)signal(3tcl)NAME
signal - dynamically loadable signal handling for Tcl/Tk
SYNOPSIS
signal (add|delete|print|version) [options]
COMMANDS
add signo proc [-async]
Adds a signal handler for signal signo through proc proc. Signals can be provided by number, or the most common ones are provided by name
(e.g., SIGHUP). The proc is any Tcl procedure, and it is evaluated when the signal comes in. It will be provided no arguments.
Signal handlers have Posix semantics - they persist until reset.
If -async is used, the signal handler is created using Tcl_AsyncCreate(). Checks for the signal are very frequent (each evaluation) using
this technique, but one doesn't know quite where evaluation is or how to handle errors in this situation. The code will evaluate the pro-
vided procedure in the current interpreter if available, and in the interpreter which added the signal handler otherwise. At least until a
better scheme is suggested.
The -async is especially useful to interrupt "runaway" procs, or to cause a quick exit; the default mechanism simply waits for another
MainLoop cycle.
signal delete signo
Restores handling of signal signo to the default ( SIG_DFL ).
signal print
Prints the handling of all signals with handlers. Formatted as
signal ----> procedure or as
signal !---> procedure
if the signal is handled asynchronously
signal print signo
Prints the procedure for handling signal signo. Prints the word UNHANDLED if no signal handler is active for that signal.
signal version
Returns the string representing the current version of the package
AUTHOR
Michael Schwartz <mschwart@nyx.net>. Tilman Kranz <tilde@tk-sls.de> patched this for wider portability on Linux
Tcl Signal Extension 1.4.0.1 Tcl signal(3tcl)
Check Out this Related Man Page
PCNTL_SIGNAL_DISPATCH(3) 1 PCNTL_SIGNAL_DISPATCH(3)pcntl_signal_dispatch - Calls signal handlers for pending signalsSYNOPSIS
bool pcntl_signal_dispatch (void )
DESCRIPTION
The pcntl_signal_dispatch(3) function calls the signal handlers installed by pcntl_signal(3) for each pending signal.
RETURN VALUES
Returns TRUE on success or FALSE on failure.
EXAMPLES
Example #1
pcntl_signal_dispatch(3) example
<?php
echo "Installing signal handler...
";
pcntl_signal(SIGHUP, function($signo) {
echo "signal handler called
";
});
echo "Generating signal SIGHUP to self...
";
posix_kill(posix_getpid(), SIGHUP);
echo "Dispatching...
";
pcntl_signal_dispatch();
echo "Done
";
?>
The above example will output something similar to:
Installing signal handler...
Generating signal SIGHUP to self...
Dispatching...
signal handler called
Done
SEE ALSO pcntl_signal(3), pcntl_sigprocmask(3), pcntl_sigwaitinfo(3), pcntl_sigtimedwait(3).
PHP Documentation Group PCNTL_SIGNAL_DISPATCH(3)
I want to catch multiple instances of same signals serially ie the signal handler should be invoked recursively for multiple instances of the same signal.How it is possible ? (12 Replies)
Looking for a document that indicates the signal values and what they mean. Found this of AIX under /usr/include/sys/signal.h only Sun sol did not find same type of information. (3 Replies)
Hi folks
I'm trying to write a signal handler (in c on HPUX) that will catch the child process launched by execl when it's finished so that I can check a compliance file.
The signal handler appears to catch the child process terminating however when the signal handler completes the parent... (3 Replies)
I am using the signal function, and passing it a function named quit procedure...I get the following warning....
passing arg2 of signal from incompatible pointer type...
void quit_procedure(void); //this is the way i define my prototype...
signal(SIGINT, quit_procedure);
Please guide... (5 Replies)
Hey folks,
i need communicate between 2 processes in a reliable manner. The information delivery has to be guarenteed. I thought about proc 2 sending a signal to proc 1 when information has being written to disc and wirte() has been verified (sync/flush). The IPC method for the data is named... (4 Replies)
Hey guys,
I am trying to write a little shell, and was writing a signal handler to handle SIGINT (I am using 'stty intr ^C' and using ctrl-C to give SIGINT).
I wrote this signal handler: void handle_sigint()
{
write(2,"handling sigint\n",16);
write(1,"\nshell% ",8);
}
... (4 Replies)
Hello all,
I am starting to learn signal handling in Linux and have been trying out some simple codes to deal with SIGALRM. The code shown below sets a timer to count down. When the timer is finished a SIGALRM is produced. The handler for the signal just increments a variable called count. This... (7 Replies)
Is it ok to use exit() inside a signal handler?
I catch SIGUSR1 in a signal handler and I try to close a file and then exit. The result is inconsistent. Sometimes the process exit and sometimes it returns to the original state before the signal handler was invoked.
Perhaps exit is not legal in... (8 Replies)
Hi!
I want to catch all signals that my program receives print their name and then execute the default handler.
Can you help me on that?
I've tried the following code:
#include <stdio.h>
#include <unistd.h>
#include <signal.h>
void (*hnd)(int i);
char signals =
{
"SIGHUP",... (7 Replies)
Hi guys,
this is my first posting, so at first hi to everyone! ;)
I have a problem with ucontext_t in connection with signal handling. I want to simulate a preemptive scheduler. I am using the iTimer with ITIMER_PROF, to schedule the interrupts. You find the code below:
#include <stdio.h>... (18 Replies)
i wrote handler for sigsegv such that i can allocate memory for a variable to which
sigsegv generated for illlegal acces of memory.
my code is
#include <signal.h>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
char *j;
void segv_handler(int dummy)
{
j=(char *)malloc(10);
... (4 Replies)
Hi,
I have a problem with signal handler algorithm in linux. My code is hanging ( It is continuously looping inside the signal handler) . I am pasting my code here...
Please provide me some help regarding this. I googled many places and wrote this code.. but doesnt seem to be working without... (6 Replies)
I want to delete a line between selected lines using sed:
e.g. : Between "bus" to "pins", delete lines conaining "signal" word.
Input :
bus
direction
signal new
signal old
pins
signal ok
end
Desired Output:
bus
direction
pins
signal
end (4 Replies)
Hello I want to know how can i use signal function in c for keyboard interrupt handling. what i exactly want is : my program is processing and if i press any key while processing , the program should call the interrupt and displays/prints that key and now goes back to processing.
I added the... (5 Replies)