use strict;

sub test {
  my $filename = 'test2.txt';
  if (-f $filename) {
    print "File Exists!";
  } else {
    print "File does not exist";
  }
}

sub openFile {
  open my $fh, '>>', 'test2.txt';
  print "file open!\n";
  print $fh "The stuff I wanted to add to the end of the file.\n";
}

test();
openFile();
test();

##</code><code>##

$: perl foo.pl
File does not exist
file open
File Exists!
$: cat test2.txt
The stuff I wanted to add to the end of the file.
$: perl foo.pl
File Exists!
file open
File Exists!
$: cat test2.txt
The stuff I wanted to add to the end of the file.
The stuff I wanted to add to the end of the file.
$: