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Newbie-- HELP! : (F) Perl was trying to evaluate a reference to a code value (that is, a subroutine), but found a reference to something else instead.

Posted on 2006-11-05
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Last Modified: 2010-03-05
Can someone PLEASE tell me what is wrong with this code.  I've been trying to figure it out for 2 hours.
i just started learning perl.  I've never seen any error like this. Not even in C.

#!/usr/bin/perl -w

###########################
###### Description     ############
### A basic site pinger ############
### ########################
###########################

use strict;
use warnings;
use diagnostics;

use Net::Ping;

if (@ARGV)
   {
      my $host = shift;
      chomp($host);
      my $err = pingIt($host);
   }
else
   {
    print "usage: pingtest <hostname>";
   }


 sub pingIt
 {
     my $p = Net::Ping->new("icmp");
     my $retStat = $p->($_[0], 4);
     $p->close();
     return($retStat);
 }
0
Comment
Question by:TristinColby
  • 2
4 Comments
 
LVL 6

Expert Comment

by:tone28
ID: 17876145
#!/usr/bin/perl -w

###########################
###### Description     ############
### A basic site pinger ############
### ########################
###########################

use strict;
use warnings;
use diagnostics;

use Net::Ping;

if (@ARGV)
   {
      my $host = shift;
      chomp($host);
      my $err = pingIt($host);
        if($err) {
            print $err;
          }
        else {
            print "Not init";
        }
   }
else
   {
    print "usage: pingtest <hostname>";
   }


 sub pingIt
 {
     my $p = Net::Ping->new("icmp");
     my $retStat = $p->ping($_[0], 4);
     $p->close();
     return($retStat);
 }



in the pinigIt sub you forgot to add ping to the p->($_[0],4)  --> p->ping($_[0],4)


0
 
LVL 17

Expert Comment

by:mjcoyne
ID: 17876153
sub pingIt
 {
     my $p = Net::Ping->new("icmp");
     my $retStat = $p->ping($_[0], 4);
     $p->close();
     return($retStat);
 }
0
 
LVL 17

Expert Comment

by:mjcoyne
ID: 17876160
Oops -- tone28 beat me to it.  Note that you might also want to scope $host and $err outside of the "if" loop if you'll want to use them elsewhere:

#!/usr/bin/perl -w

###########################
###### Description     ############
### A basic site pinger ############
### ########################
###########################

use strict;
use warnings;
use diagnostics;
use Net::Ping;

my ($host, $err);

if (@ARGV)
   {
      $host = shift;
      chomp($host);
      $err = pingIt($host);
   }
else
   {
    print "usage: pingtest <hostname>";
   }

 sub pingIt
 {
     my $p = Net::Ping->new("icmp");
     my $retStat = $p->ping($_[0], 4);
     $p->close();
     return($retStat);
 }
0
 
LVL 48

Accepted Solution

by:
Tintin earned 250 total points
ID: 17877381
I'd write it as

#!/usr/bin/perl
use strict;
use warnings;
use diagnostics;
use Net::Ping;

die "USAGE: $0 <hostname>\n" unless @ARGV;
my $err = pingIt(@ARGV);

sub pingIt {
     my $host = shift;

     my $p = Net::Ping->new("icmp");
     my $retStat = $p->ping($host, 4);
     $p->close();
     return $retStat ;
}
0

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