This tidies your [PATH](). Usage:
```bash
PATH="$(tidypath -c "$HOME/bin" "/path/to/in" -p)"
```
where `-c` means it checks for the presence of each directory, and `-p` inserts the current [PATH]().
I usually use [Python](/aw/lang/python) these days, but [Perl](/aw/lang/perl) starts more quickly, and that is important when this is called from your `.bashrc`.
```
#!/usr/bin/perl
# give PATH variable(s) on the command line
# duplicates are removed, and with the -c option, non-existing directories are removed
%a = ();
@a = ();
$check = 0;
for(@ARGV) {
  if($_ eq "-c") {
    $check = 1;
    next;
  }
  if( $_ eq "-p" ) {
    $_ = $ENV{"PATH"};
  }
  @b = split /:/;
  for $b(@b) {
    unless($a{$b}) {
      $a{$b} = $b;
      next unless(! $b eq "");
      next if( $check and ! -d $b );  # skip nonexisting paths
      push @a, $b;
    }
  }
}
$p = join ":", @a;
print $p."\n";
```