use YAML;

...
my $options = YAML::LoadFile($fileName);

...

YAML::DumpFile($fileName, $options);

##</code><code>##

---
alarm: AlarmHorn.wav
courts:
  - avail: 1
    name: Court 1
    players: 4
    size: 4
  - avail: 1
    name: Court 2
    players: 4
    size: 4
  - avail: 1
    name: Court 3
    players: 4
    size: 4
fontSize: 12
geom: 630x470
time: 720