in reply to How to tell Child wait till Parent kill it

In the child process, set up a signal handler. A standard kill sends out the TERM signal, but you can wait for any signal, and react accordingly. Here's an example:

use strict;
use warnings;

$SIG{HUP}  = \&sighup_handler;
$SIG{TERM} = \&sigterm_handler;

sleep(3600);

sub sigterm_handler {
    die "Caught TERM, will not do anything!";
}

sub sighup_handler {
    # commit changes to the database and exit
}

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- Luke

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Re^2: How to tell Child wait till Parent kill it
by gjoshi (Sexton) on Nov 20, 2015 at 04:36 UTC
    Hi Luke, I am not getting where in my code i have to do this and how to do this? 
    
$SIG{HUP}  = \&sighup_handler;
$SIG{TERM} = \&sigterm_handler;

#----------------------------- MAIN ----------------------------
print "I am the only process.\n";
my @children_pids;


for my $count (1..3){
        my $child_pid = fork();
        print "PID: $child_pid \n";
        if ($child_pid) {  # If I have a child PID, then I must be the
+ parent
                push @children_pids, $child_pid;
        }
        else { # I am the child
                my $Child_PID = $$;
                print "CHILD's PID is: $Child_PID \n";
                #doing something
                # writing into DB
                sleep $wait_time;
        }
}

print "\n ----- Main DB ---- \n";
foreach my $child (@children_pids) {
        print "Parent: Waiting on $child\n";
        #check DB stats
        #send kill signal
        waitpid($child, 0);
}

    [download]
    thanks --girija
[reply]
[d/l]

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