my $found = 0;
open(FH, "$filename") || die "Cannot open $filename for reading: $!\n";
while (<FH>) {
  chomp;
  my (email,name) = split('=',$_);
  if ($email eq $inputted_email) {
    $found = 1;
    break;  ## exit loop;
  }
}
close FH;

if (!$found) {
  ## Append to file
  open(FH, "<<", "$filename") || die "Cannot open $filename to append: $!\n";
  print FH, "$inputted_email=$inputted_name\n";
  close FH;
}