while(<NODE>){
    push(@lines, $_);
}
[download]

In list context, the diamond operator returns the entire file, so you can avoid the loop:

push( @lines, <NODE> );
[download]

---

In if statements, pull out the common code, so that your code shows the differences, and the reader doesn't have to figure out what's different:

if($is_script eq 'yes'){
      middle();
      bottom();
  } else {
      top();
      middle();
      bottom();
  }
[download]

is better as

top() unless ($is_script eq "yes");
middle();
bottom();
[download]

xoxo,
Andy

%_=split/;/,".;;n;u;e;ot;t;her;c; ".   #   Andy Lester
'Perl ;@; a;a;j;m;er;y;t;p;n;d;s;o;'.  #   http://petdance.com
"hack";print map delete$_{$_},split//,q<   andy@petdance.com   >