Install perl really fast

Fastest way to install perl:

perlbrew install -j 5 --notest perl-5.16.3

Only takes about 2 mins.

Thanks perlbrew.

When to use "or" and when to use || (double pipe) in Perl

Use || for assigning to a variable:

$a = $b || $c

Use "or" to control program flow:

$a = $b or die 'error: $b is unexpectedly false'

Mnemonic: || is a symbol like variables and numbers are, while "or" and "die" are both english words.

(source, source)