Maybe you could open a pipe to the second process, instead of invoking a system call to it. Or, save the large array as a file, and pass the filename to the second process.

Also, you've got a problem with the snippet you posted. The semicolon after the system call terminates the sentence, so to speak. So the "or die..." portion is its own separate statement. You meant to say:

! system ( "perl", $perl_file, $comp, $warn_list_arg) or die "Program 
+exit";
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As for how to open a pipe, see perlopen and perlopentut.