First, install the perl module BSD::Resource
yum install perl-BSD-Resource
Then use it in your program like:
#!/usr/bin/perl
use BSD::Resource; setrlimit(RLIMIT_VMEM, 1_000_000, 1_000_000);
# rest of the program that is limited to 1MByte now
Thanks, Paul. I knew I'd find an answer if I posted my question here.