'out of memory' errors

[tom arnall <kloro2006@gmail.com>]

i am trying to us a perl application that handles large files (.5GB) in scalar 
variables.  when i try to  'slurp' one of these files into a variable 
(e.g., '$_ = `cat filename`) i get an out of memory error. (same for '@var = 
<FH>') initially, i ran the script without any memory limits. that was fine 
except the process would freeze the rest of the system. i dealt with this 
problem by setting limits for myself in /etc/security/limits.conf as follows;


	kloro	hard   	rss	   	256000
	kloro	hard   	memlock     256000
	kloro	hard   	as	       	768000
	
now, tho' i get 'out of memory' errors. 

is there not some way to get linux to use swap space when physical memory is 
exceeded?

thanks,

tom arnall
north spit, ca