Signal Handling in a Child Process

[anshumangoyal]

I am forking a child process (a perl file is called in that child process) and in that child there is a Signal Handling Routine written. I want that when I send a signal to this child (SIG USR1), it should exit giving return code 110. This is my Code:

    $SIG{USR1} = 'HANDLER';
    sub HANDLER {
        print "Got 'USR1'. Exiting with Return Code '110' !!\n";
        exit 110;
    }

But with this it exits from Handler with 110 and not from the child. Is there anything I am doing wrong here?

[aitap]

Perhaps you need to use local there?

$ perl -E'
if (my $pid = fork) {
 say "My pid is $$, child is $pid";
 local $SIG{USR1} = sub { say "parent"; exit 0 };
 sleep 1 while 1
} else {
 local $SIG{USR1} = sub { say "child"; exit 0 };
 sleep 1 while 1
}' &
[1] 19681
My pid is 19681, child is 19683
$ kill -USR1 19683
child
$ kill -USR1 19681
parent
[1]+  Done                    perl -E'if (my $pid = fork) { say "My pi
+d is $$, child is $pid"; local $SIG{USR1} = sub { say "parent"; exit 
+0 }; sleep 1 while 1 } else { local $SIG{USR1} = sub { say "child"; e
+xit 0 }; sleep 1 while 1}

Or have I misunderstood something?

[Illuminatus]

I am forking a child process (a perl file is called in that child process)...

I'm not sure what you mean here. Do you mean that you are forking a child that is, in turn, forking a perl script?. When I run the following:

#! /usr/bin/perl

    sub HANDLER {
        print "Got 'USR1'. Exiting with Return Code '110' !!\n";
        exit 110;
    }

$SIG{USR1} = 'HANDLER';
while (1) {
    sleep(60);
}

In background, and send SIGUSR1 to it, it immediately exits with code 110 (if only the HANDLER function had returned, the script would have continued to run).

fnord