$0 Contains the name of the program being executed. On some (but not all) operating systems assigning to
$FORMAT_TOP_NAME
$^N The text matched by the used group most-recently closed (i.e. the group with the rightmost closing parenthesis) of the last successful
$^W The current value of the warning switch, initially true if -w was used, false otherwise, but directly modifiable.
$] The revision, version, and subversion of the Perl interpreter, represented as a decimal of the form 5.XXXYYY, where XXX is the version /
@ARG
$INPUT_RECORD_SEPARATOR
%SIG The hash %SIG contains signal handlers for signals. For example:
$PID
IO::Handle->input_record_separator( EXPR )
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