Posted about 8 years ago. Visible to the public. Linked content.
Cryptic Ruby Global Variables and Their Meanings
The linked page lists and explains global Ruby "dollar" variables, such as:
$?(Last exit status)
MatchDatafrom last successful match)
- ...and many more you'll need when reading weird code.
$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