$LAST_SUBMATCH_RESULT

$EXECUTABLE_NAME

$EUID

${^LAST_FH} This read-only variable contains a reference to the last-read filehandle. This is set by

${^OPEN} An internal variable used by PerlIO. A string in two parts, separated by a \0 byte

$OSNAME

$^A The current value of the write() accumulator

HANDLE->format_lines_per_page(EXPR)

IO::Handle->input_record_separator( EXPR )

$REAL_USER_ID