#!/usr/bin/perl

use strict;
use warnings;
 
use IO::Socket::INET;
 
my @host = qw[ 192.168.1.3 192.168.46.2 ];
my $port = 22;
 
foreach (@host)
{
     check($_, $port);
}
 
sub can_connect
{
     my ($ip, $port) = @_;

     return ! !IO::Socket::INET->new(
                         PeerAddr => $ip,
                         PeerPort => $port,
                         Proto    => 'tcp',
                         timeout  => 10,
     );
}

sub check
{
     my ($ip, $port) = @_;
     my $can_connect = can_connect($ip,$port);

     print "$ip is ";
     print "NOT" unless ($can_connect);
     print " listening on port $port\n";

     return $can_connect;
}

sub check_variation
{
     my $can_connect = can_connect(@_);

     print "$ip is ";
     print "NOT" unless ($can_connect);
     print " listening on port $port\n";

     return $can_connect;
}
[download]

> I think that edges into obfuscation territory. What about this?

I call that obfuscation through abundance. :-)

...All the world looks like -well- all the world, when your hammer is Perl.
---v

Note: I could have sworn I sent this in yesterday... bah.

My code edges into obfuscation? How about your double-negative return? ^^;;

++ on your modifications, but might I suggest:

#!/usr/bin/perl

use strict;
use warnings;
 
use IO::Socket::INET;
 
my @host = qw[ 192.168.0.5 66.100.167.57 ];
my $port = 22;
 
foreach (@host)
{
     check($_, $port);
     check_variation($_, $port);
     check_complication($_,$port);
}
 
sub can_connect
{
     my ($ip, $port) = @_;

     return ! !IO::Socket::INET->new(
                         PeerAddr => $ip,
                         PeerPort => $port,
                         Proto    => 'tcp',
                         timeout  => 10,
     );
}

sub check
{
     my ($ip, $port) = @_;
     my $can_connect = can_connect($ip,$port);

     print "$ip is ";
     print "NOT " unless ($can_connect);
     print "listening on port $port\n";

     return $can_connect;
}

sub check_variation
{
     # changed this so Strict doesn't complain
     my $can_connect = can_connect(my ($ip,$port) = @_);

     print "$ip is ";
     print "NOT " unless ($can_connect);
     print "listening on port $port\n";

     return $can_connect;
}

sub check_complication
{
     print "$_[0] is ".($_?"":"NOT ")."listening on port $_[1]\n" 
          and 
     return $_
          for 
     can_connect(@_);
}
[download]

When I was in high school I had a friend who believed he didn't have bad handwriting because, after all, he could read at least 85% of it. In that vein, "this isn't obfuscation!"


LAI
:eof

The double-negative is, of course, to replicate the functionality of the earlier function which returned either 1 or undef. Invert once, and you get 1 on false, undef on true. Invert again, and you get 1 on true, undef on false.

It's a cheap trick, and using !! can even throw off some syntax highlighters, so I tend to space it out.

Here's another way to do it:

my $foo = (....) && 1;

> But then again, I'm a sucker for the ternary operator.

...I like that. I must confess to the same weakness.

...All the world looks like -well- all the world, when your hammer is Perl.
---v