Robert's Perl Tutorial

http://www.sthomas.net/roberts-perl-tutorial.htm


When to use external calls

Before you get carried away with creating elaborate scripts based on the output from NT's net commands, note there are plenty of excellent modules out there which do a very good job of this sort of thing, and that any form of external process call slows your script. Also note there are plenty of built in functions such as readdir which can be used instead of `dir` . You should use Perl functions where possible rather than calling external programs because Perl's functions are:

Don't start using backticks all over the place when system will do. You might get a very large return value which you don't need, and will consequently slurp lots of memory. Just use them when you actually want to check the returned strings.