$= The current page length (printable lines) of the currently selected output channel. The default is 60. Mnemonic:

$] The revision, version, and subversion of the Perl interpreter, represented as a decimal of the form 5.XXXYYY, where XXX is the version /

${^TAINT} Reflects if taint mode is on or off. 1 for on (the program was run with -T), 0 for off, -1 when only taint warnings are enabled

ARGVOUT The special filehandle that points to the currently open output file when doing edit-in-place processing with -i. Useful when

@ARG

$^ The name of the current top-of-page format for the currently selected output channel. The default is the name of the filehandle with

${^PREMATCH} This is similar to $` ($PREMATCH) except that it does not incur the performance

@- $-[0] is the offset of the start of the last successful match

$b Special package variables when using sort()

%ERRNO