my $var_one;
sub copy_file {
  open(IFILE, "<afile");
  while($x = <IFILE>) {$x =~ s|(\$\w+)|$1|eeg; print $x};
  close(IFILE);
}

copy_file();

##</code><code>##

my $var_one;
sub copy_file {
  my $var_one = $var_one;
  open(IFILE, "<afile");
  while($x = <IFILE>) {$x =~ s|(\$\w+)|$1|eeg; print $x};
  close(IFILE);
}

##</code><code>##

my $var_one;
sub copy_file {
  my $x = "<p>The variable is $var_one.</p>";
  $x =~ s|(\$\w+)|$1|eeg; print $x;
}

##</code><code>##

sub copy_file {
  open(IFILE, "<afile");
  while($x = <IFILE>) {$x =~ s|(\$\w+)|$1|eg; print $x};
  close(IFILE);
}