=over =item $^M By default, running out of memory it is not trappable. However, if compiled for this, Perl may use the contents of C<$^M> as an emergency pool after die()ing with this message. Suppose that your Perl were compiled with -DPERL_EMERGENCY_SBRK and used Perl's malloc. Then $^M = 'a' x (1<<16); would allocate a 64K buffer for use when in emergency. See the F file for information on how to enable this option. As a disincentive to casual use of this advanced feature, there is no L long name for this variable. =back