Hello, all. I have a short perl script that is a nagios plugin. It checks the RF speed of a radio. It works well, as long as the IP target exists. Today I found that when the radio I'm querying is hard down, the snmpwalk command times out, but my (admittedly very poor) code doesn't catch the timeout. 
#!/usr/bin/perl -w
use strict;

my $radio = $ARGV[0];
my $warnrate = $ARGV[1];
my $critrate = $ARGV[2];

if ($critrate <= $warnrate) {
open DATA, "/usr/bin/snmpwalk -v1 -c public $radio .1.3.6.1.4.1.5454.1
+.40.2.4.0|" or die "Failed: $!\n";

while ( defined( my $line = <DATA> )  ) {
        my @values = split(' ', $line);
        my $score = $values[3];
    close DATA;
        if ($score > $warnrate) {
            print "OK, rf is $score. \|Mbps=$score\n";
                exit 0
            } elsif (($score <= $warnrate) && ($score > $critrate)) {
            print "WARNING, rf is $score. \|Mbps=$score\n";
                exit 1
            } elsif ($score <= $critrate) {
            print "CRITICAL, rf is $score. \|Mbps=$score\n";
                exit 2
            } else {
            print "UNKNOWN, rf is $score and something is wrong.\n";
                exit 3
            }
}
} else {
print "Make sure your critical value is less than or equal to your war
+ning value.\n";
exit 5}

[download]
I would think since the snmpwalk on a radio that doesn't exist timesout, the $score variable should either be null or 0, either of which should trigger either the unknown or critical conditions, or the whole script should exit with exit code 5. As I found today, with the radio unreachable and the snmpwalk timing out, this script still exits with an exit code of 0, indicating all is well.

I'd apprecaite any insight folks can provide into what I've done wrong here.

In reply to What did I miss in my test condition? by jimbass

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