Listing 4. /home/ejb/moni/monitor.pl
#!/usr/bin/perl -Tw
use strict;
my $FIFO = '/tmp/tricky.fifo';
my $DIALDCTL = '/etc/diald/diald.ctl';
my $STATUS = '/tmp/diald.status';
my $st = 0;
my $dialdState = "DOWN";
$SIG{CHLD} = sub { wait };
unless (-p $FIFO) {
unlink $FIFO;
system('/usr/bin/mkfifo','-m','666',$FIFO) &&
die "Can't mkfifo $FIFO: $!";
}
my $pid;
if ($pid = fork) {
open (FIFO, "< $FIFO") ||
die "can't read $FIFO: $!";
} elsif (defined $pid) {
open (DIALDCTL, "> $DIALDCTL") ||
die "can't open $DIALDCTL: $!";
print DIALDCTL "monitor $FIFO\n";
close DIALDCTL;
exit;
} else {
die "Can't fork: $!\n";
}
my $msg = 0;
open (STATUS, "> $STATUS") ||
die "can't open status file $STATUS: $!";
select STATUS;
$| = 1; # set flush-on-write
while (<FIFO>)
{
if ($st == 1) {
$st = 0;
if (m/^CONNECT/) {
close STATUS;
unlink $STATUS;
open (STATUS, "> $STATUS") || die
"can't open status file $STATUS: $!";
select STATUS;
}
print;
}
if ($msg == 1) {
$msg = 0;
print;
}
if (m/^STATE/) {
$st = 1;
}
elsif (m/^MESSAGE/) {
$msg = 1;
}
}
Copyright © 1994 - 2018 Linux Journal. All rights reserved.