Re: How to verify if a daemon is up and running ?


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Re: How to verify if a daemon is up and running ?

by rob_au (Abbot)

on Dec 03, 2002 at 20:53 UTC ( [id://217343]=note: print w/replies, xml )

Need Help??

in reply to How to verify if a daemon is up and running ?

I would recommend the usage of Proc::ProcessTable which I have reviewed previously on this site here. Using Proc::ProcessTable, your code would look something like this:

use Proc::ProcessTable;

my $running = 0;
my $proc = Proc::ProcessTable->new;
foreach ( @{ $proc->table } ) {
    if ($_->cmndline =~ /testd/) {
        ++$running;
    }
}
if (!$running) {
    #   do something to reinvoke process
}
[download]

This code will count the number of testd processes running on the system, returned in $running, which should allow you to determine whether this existing process should continue execution.

The other approach to this problem would be to incorporate a process identification or lock file, as suggested by Ryszard above, which can be monitored external the current execution process.

perl -le 'print+unpack("N",pack("B32","00000000000000000000000111110001"))'