=head1 NAME
-perlfaq3 - Programming Tools ($Revision: 1.21 $, $Date: 2002/04/28 15:51:10 $)
+perlfaq3 - Programming Tools ($Revision: 1.22 $, $Date: 2002/05/06 13:11:13 $)
=head1 DESCRIPTION
( http://www.textpad.com/ ) and UltraEdit
( http://www.ultraedit.com/ ), among others.
-If you are using MacOS, the same concerns apply. MacPerl
+If you are using Mac OS, the same concerns apply. MacPerl
(for Classic environments) comes with a simple editor.
Popular external editors are BBEdit ( http://www.bbedit.com/ )
-or Alpha ( http://www.kelehers.org/alpha/ ). MacOS X users can
+or Alpha ( http://www.kelehers.org/alpha/ ). Mac OS X users can
use Unix editors as well.
=over 4
=head2 How can I free an array or hash so my program shrinks?
-You can't. On most operating systems, memory allocated to a program
-can never be returned to the system. That's why long-running programs
-sometimes re-exec themselves. Some operating systems (notably,
-FreeBSD and Linux) allegedly reclaim large chunks of memory that is no
-longer used, but it doesn't appear to happen with Perl (yet). The Mac
-appears to be the only platform that will reliably (albeit, slowly)
-return memory to the OS.
-
-We've had reports that on Linux (Redhat 5.1) on Intel, C<undef
-$scalar> will return memory to the system, while on Solaris 2.6 it
-won't. In general, try it yourself and see.
+You usually can't. On most operating systems, memory
+allocated to a program can never be returned to the system.
+That's why long-running programs sometimes re-exec
+themselves. Some operating systems (notably, systems that
+use mmap(2) for allocating large chunks of memory) can
+reclaim memory that is no longer used, but on such systems,
+perl must be configured and compiled to use the OS's malloc,
+not perl's.
However, judicious use of my() on your variables will help make sure
that they go out of scope so that Perl can free up that space for
projects / p5sagit/p5-mst-13.2.git / blobdiff