The linked page lists and explains global Ruby "dollar" variables, such as:
- 
$:(load path)
- 
$*(ARGV)
- 
$?(Last exit status)
- 
$$(PID)
- 
$~(MatchDatafrom last successful match)
- ...and many more you'll need when reading weird code.
Regex
- 
$~(lastMatchData)
- 
$1 $2 $3 $4(match groups from the last pattern match)
- 
$&(last matched string)
- 
$+(last match group)
- `$`` (the string before the last match)
- 
$'(the string after the last match
See this extensive list of variables Show archive.org snapshot .
Posted by Arne Hartherz to makandra dev (2013-07-17 10:19)