Perl: trap signal 'exit': why I am not able to have it work??
First time trying to work with signals in Perl.
Reviewing example I try it, but not able to get it work for 'exit'.
I hope, I am correct, assuming, that the ending any code by
the $SIG{EXIT} should be de-referenced and processed?!
So, I have such code, that, I assume, should, but does not process signal handling:
Please, help me understand what is wrong or,
if I mistaken on assumption that the 'exit()' is processed by the $SIG{EXIT}, how it could be handled to process activity, such as in UNIX 'trap "..." EXIT' command?
Does anyone know how to program signals in fmli?
My fmli script goes in loop when the telnet session is closed. When I start the script from the prompt the issue do not happen. But when it is started by the login process it hags. That's why I want to program the SIGHUP to exit/finish the script.... (0 Replies)
hey champs,
I have a process running.......i have to catch/trap the signal when the process is being interupted/killed (kill -9 pid) option......
how can i achieve the same thru my process........
let my process is a.sh and it supposed to take 13 mins to complete, but due to some problem ,... (15 Replies)
Hi,
I have a trap problem when calling a child script in the background.
I know there are a lot of threads here on the issue of traps and signals, I think I have read all the relevant ones, but still haven't found an answer to my problem.
I'm working on Linux or HP, the script as you can see... (4 Replies)
I just want to trap kill -9 signal issued by any of user from any terminal and just capture that user terminal who had raised this kill -9 command (1 Reply)
In my Bash script I have an exit/cleanup function in a trap statement like:
trap exitCleanup 1 2 3 6 15 25
Is there anyway to capture which signal # has occurred to record in a log file. Please note I am trying to avoid something like:
trap 'mySignal=1; exitCleanup' 1
trap... (1 Reply)
Hi ,
i have a scenario where...i have to put a check where if script is executing more than 15mins i have to kill that script and n retry again 2nd time.
i this case i can use background process to do it but i feel trap will be the efficent way to do so...
but i dont know much about it... (1 Reply)
Hi, I would like to ask, if is it possible to quit running loop in the script any other way than catching the trap signal. Ctrl-C ends only current running instance of process but not whole script. Any clues? (3 Replies)
Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!
1. The problem statement, all variables and given/known data:
That is the last reply I received from my instructor, and I'm looking for some alternatives.
When using... (2 Replies)
Discussion started by: newuser45
2 Replies
LEARN ABOUT OSX
net::server::sig
Net::Server::SIG(3) User Contributed Perl Documentation Net::Server::SIG(3)NAME
Net::Server::SIG - adpf - Safer signal handling
SYNOPSIS
use Net::Server::SIG qw(register_sig check_sigs);
use IO::Select ();
use POSIX qw(WNOHANG);
my $select = IO::Select->new();
register_sig(PIPE => 'IGNORE',
HUP => 'DEFAULT',
USR1 => sub { print "I got a SIG $_[0]
"; },
USR2 => sub { print "I got a SIG $_[0]
"; },
CHLD => sub { 1 while waitpid(-1, WNOHANG) > 0; },
);
# add some handles to the select
$select->add(*STDIN);
# loop forever trying to stay alive
while(1) {
# do a timeout to see if any signals got passed us
# while we were processing another signal
my @fh = $select->can_read(10);
my $key;
my $val;
# this is the handler for safe (fine under unsafe also)
if (check_sigs()) {
# or my @sigs = check_sigs();
next unless @fh;
}
my $handle = $fh[@fh];
# do something with the handle
}
DESCRIPTION
Signals prior in Perl prior to 5.7 were unsafe. Since then signals have been implemented in a more safe algorithm. Net::Server::SIG
provides backwards compatibility, while still working reliably with newer releases.
Using a property of the select() function, Net::Server::SIG attempts to fix the unsafe problem. If a process is blocking on select() any
signal will short circuit the select. Using this concept, Net::Server::SIG does the least work possible (changing one bit from 0 to 1).
And depends upon the actual processing of the signals to take place immediately after the the select call via the "check_sigs" function.
See the example shown above and also see the sigtest.pl script located in the examples directory of this distribution.
FUNCTIONS
"register_sig($SIG => &code_ref)"
Takes key/value pairs where the key is the signal name, and the argument is either a code ref, or the words 'DEFAULT' or 'IGNORE'. The
function register_sig must be used in conjuction with check_sigs, and with a blocking select() function call -- otherwise, you will
observe the registered signal mysteriously vanish.
"unregister_sig($SIG)"
Takes the name of a signal as an argument. Calls register_sig with a this signal name and 'DEFAULT' as arguments (same as
register_sig(SIG,'DEFAULT')
"check_sigs()"
Checks to see if any registered signals have occured. If so, it will play the registered code ref for that signal. Return value is
array containing any SIGNAL names that had occured.
"sig_is_registered($SIG)"
Takes a signal name and returns any registered code_ref for that signal.
AUTHORS
Paul Seamons (paul@seamons.com)
Rob B Brown (rob@roobik.com) - Provided a sounding board and feedback in creating Net::Server::SIG and sigtest.pl.
LICENSE
This package may be distributed under the terms of either the
GNU General Public License
or the
Perl Artistic License
All rights reserved.
perl v5.16.2 2012-05-29 Net::Server::SIG(3)