If you don't understand it, why use it? Is it that important for you to do this in one line of (relatively obscured) code, than in 2-3 lines of readable code?

If you don't understand it, why use it? Is it that important for you to do this in one line of (relatively obscured) code, than in 2-3 lines of readable code? For the record, the do() block defines @ARGV (which normally holds the command-line arguments) to contain the value of the $file (presumably a file name), and sets $/ (which is the input record separator) to an undefined value. In Perl, <> is synonymous to <STDIN> which makes it read from stdin. Since @ARGV now contains a file name, Perl will open this file for reading. Since $/ is undefined, Perl will enter in "slurp" mode, and will gobble up the whole file in one shot. Since this is the last statement in the do() block, it will be returned as its value, and stored in $text. Lots of Perl magic happening here. I advise you against using such shortcuts.