FOREACH Variables

[tx_sailor]

Greeting Monks,

I am new to PERL so forgive me if this is a trival question. I am building a script to be run via Openview to query an SNMP MIB for get status of an indexed interface. Based on the description of the interface and status, I want to formulate a custom trap.

At this point, I am using Net::SNMP to gain the information from the network device using SNMPv1 (only support by device). Where I am running into trouble is exacting the variables from the FOREACH loop so I can utilize them in a if/else loop. I started from a well know bit of code and modified it.

Here is the code so far:

 

#!/usr/local/bin/perl

# use strict;

use Net::SNMP '5.0' || die("Cannot Load SNMP Module\n");
############################## CONFIGURATION #########################
+#########

$snmpnotify = "nnmsnmpnotify.ovpl";
$trap3 = ".1.3.6.1.4.1.13169.9999.0.5";  #Context trap with informatio
+n(used by the Pairwise correlation)
#$snmp_target = '10.180.89.81';
$snmp_target = '';
$snmp_community = '$@g3on';

########### Check to see that the number of args is correct ##########
+#########
if (!($#ARGV == 0)){
  exit 1;
}

$snmp_target = $ARGV[0];
################################### OIDs #############################
+#########

my $oid_ifIndex = '.1.3.6.1.4.1.13169.1.2.10.4.1.1';
my $oid_ifDescr = '.1.3.6.1.4.1.13169.1.2.11.5.1.3';
my $oid_ifOperStatus = '.1.3.6.1.4.1.13169.1.2.10.4.1.2';

my @interfaceList = [$oid_ifDescr, $oid_ifOperStatus];

################################### CODE #############################
+#########

my ($session, $error, $result, @ifindex, $key);

my %alarmpoint_status = ( 1 => 'off',
                          2 => 'on',
                          3 => 'unknown');

######################################################################
+#########


## Creation Session
($session, $error) = Net::SNMP->session(
                          -hostname  => shift || $snmp_target,
                          -community => shift || $snmp_community,
                          -port      => shift || 161,
                          -version     => 'snmpv1'
                        );
if (!defined($session)) {
    printf("ERROR: %s.\n", $error);
    exit 1;
}

## Get AlarmPoint Indexes
$result = $session->get_table( -baseoid => $oid_ifIndex );
    printf("%s\n",
       $result
       );
    if (!defined($result)) {
       printf("ERROR: %s.\n", $session->error);
       $session->close;
    exit 1;
}

foreach $key ($session->var_bind_names) {
    push(@ifindex, $result->{$key});
}

## Get AlarmPoint Details
$result = $session->get_entries( -columns => @interfaceList);
    printf("%s\n",
       $result
       );
    if (!defined($result)) {
       printf("ERROR: %s.\n", $session->error);
       $session->close;
    exit 1;
}

## Loop through indexes and Output Interface Description and Status
foreach $key (@ifindex) { 
    my $alarmd =  $result->{$oid_ifDescr.'.'.$key};
    my $alarms =  $alarmpoint_status{ $result->{$oid_ifOperStatus.'.'.
+$key} };
    printf("%s : %s\n",
        $alarmd,
        $alarms
        );
    }
    
### Here is where I want to take the value $alarmd and $alarms and uti
+lize them in an if state like below:
    
   if ($alarms = "off") {
    $cmd = `$snmpnotify -v 2c -a $snmp_target 10.180.52.58 $trap3 1.3.
+6.1.4.1.13169.9999.5.1 OCTETSTRINGASCII $alarmd "Alarm" 1.3.6.1.4.1.1
+3169.9999.5.2 OCTETSTRINGASCII $snmp_target 1.3.6.1.4.1.13169.9999.5.
+3 OCTETSTRINGASCII $alarms`;
    } 
    else {}

$session->close;

Any thoughts would be greatly appreciated as I cannot seem to figure this out. Since it is SNMPv1 the getbulk and other options do not work.

Thanks

Rick

[NetWallah]

Couldn't you just move the "if ($alarms.." inside the "foreach $key.." loop ?

BTW - why is "use strict;" commented out ?

You should probably change "foreach $key ..." to "foreach my $key...", and "my $cmd=..." instead of $cmd=..." .. but then you do not use $cmd, so just use the backtick without assigning it to anything.

[snoopy]

Another catch:

use Net::SNMP '5.0' || die("Cannot Load SNMP Module\n");

is interpreted as:

use Net::SNMP ('5.0' || die("Cannot Load SNMP Module\n"));

Just stick to:

use Net::SNMP '5.0';

Perl will die anyway, if it can't find and load the module.

[jbt]

Do you mean:

if ($alarms = "off") {

or:

if ($alarms eq "off") {

[cdarke]

To clarify, $alarms = "off" is an assignment. Use == to test for numeric equality or eq to test for textual equality.

Always

use strict;
use warnings;

Although not related to your question, you are over-using printf, which is (allegedly) slower than print. Perl, and several other languages, has interpolation - when a scalar or array variable is enclosed inside double-quotes it translates to its value. This is one of the advantages of the $ and @ prefixes. So:

printf("%s : %s\n",
        $alarmd,
        $alarms
        );

is better written as:

print "$alarmd : $alarms\n";

and error messages should really be routed to stderr:

print STDERR "ERROR: $error.\n";

[snoopy]

Also,

if ($alarms = "off") {
    #...
}

should be:

if ($alarms eq "off") {
    # ...
}

[GrandFather]

which the OP would have caught with use warnings of course.