$PERL_VERSION

$ORS

$^D The current value of the debugging flags. May be read or set. Like its command-line equivalent, you can use numeric or symbolic values

$COMPILING

%ENV The hash %ENV contains your current environment. Setting a value in

%OS_ERROR

HANDLE->format_page_number(EXPR)

$ERRNO

${^RE_DEBUG_FLAGS} The current value of the regex debugging flags. Set to 0 for no debug output even when the re

%! Each element of %! has a true value only if $!