$PROGRAM_NAME

$PERLDB

${^RE_TRIE_MAXBUF} Controls how certain regex optimisations are applied and how much memory they utilize. This value by default is 65536 which

$` The string preceding whatever was matched by the last successful pattern match, not counting any matches hidden within a BLOCK or

$^E Error information specific to the current operating system. At the moment, this differs from $!

HANDLE->input_line_number( EXPR )

$( The real gid of this process. If you are on a machine that supports membership in multiple groups simultaneously, gives a space separated

$* $* was a variable that you could use to enable multiline matching. After a deprecation

$NR

$- The number of lines left on the page of the currently selected output channel. Mnemonic: lines_on_page -