Hi,

You have some good stuff in there, but the formatting makes

Question unreadable :) answer obvious :(

Dont despair :) clean your room ;)

Use the convenience that is CGI and Capture::Tiny and the Basic debugging checklist

#!/usr/bin/perl --
## perltidy -olq  -csc -csci=10 -cscl="sub : BEGIN END if while for " 
+-otr -opr -ce -nibc -i=4 -pt=0   "-nsak=*"
use strict;
use warnings;
use CGI;
use Capture::Tiny qw/ capture /;

Main( @ARGV );
exit( 0 );

sub Main {
    if( @_ ){
        Download( @_ );
    }
    elsif( my $ONLINE = CGI->new->query_string  ){
        my $url = $ONLINE;
        RunCGI();
    }
    elsif( my $url = UrlFromStdin() ){
        Download( $url );
    } else {
        PrintUsage();
    }
}

sub Download {
    my @cmd = ( 'wget', '--help' );
    my( $stdout, $stderr, $exit ) = capture {
        system { $cmd[0] } @cmd;
    };;
    die "( $stdout, $stderr, $exit )";
}
[download]

$URL needs shell escaped when given to shell

CGI.pm needs $cgi = CGI->new; $cgi->header('text/javascript') , $cgi->query_string

... String::ShellQuote , Win32::ShellQuote, Proc::Background, system_detached , use CGI or die; , ...the checklists :) Basic debugging checklist , brian's Guide to Solving Any Perl Problem, CGI Help Guide , Troubleshooting Perl CGI scripts...