still not working :(

#!/bin/Perl
use warnings;
if (@ARGV < 4) {
    print ("you need to provide 4 arguments\n\t4th argument is file to
+ parse");
    exit;
    
}

$fh = pop(@ARGV);

openfile(@ARGV);


sub openfile {
    
    open FILE1,">$_[0]" || die "could not open $_[0]";
    open FILE2,">$_[1]" || die "could not open $_[1]";
    open FILE3,">$_[2]" || die "could not open $_[2]";
    open FILE4,">$fh" || die "could not open $fh";
    
        while (my $line = <$fh>) {
    
print $line;    
}
    
    

}
[download]

i get the warning readline() on unopened filehandle at file.pl line 21. so that would be my while loop while (<$fh>) { print $line; }