See the current Perl documentation for dump.
Here is our local, out-dated (pre-5.6) version:
dump - create an immediate core dump
This causes an immediate core dump. Primarily this is so that you can use
the undump program to turn your core dump into an executable binary after having
initialized all your variables at the beginning of the program. When the
new binary is executed it will begin by executing a
goto LABEL (with all the restrictions that goto suffers). Think of it as a goto with an intervening core dump and
is omitted, restarts the program from the top.
WARNING: Any files opened at the time of the dump will
NOT be open any more when the program is reincarnated, with possible resulting confusion on the part of Perl. See also
-u option in the perlrun manpage.
#!/usr/bin/perl require 'getopt.pl'; require 'stat.pl'; %days = ( 'Sun' => 1, 'Mon' => 2, 'Tue' => 3, 'Wed' => 4, 'Thu' => 5, 'Fri' => 6, 'Sat' => 7, );
dump QUICKSTART if $ARGV eq '-d';
This operator is largely obsolete, partly because it's very hard to convert a core file into an executable, and because the real perl-to-C compiler has superseded it.