Daily Archives: 19 September, 2010

Marketing Perl

Sometimes people ask me why Perl marketing is so important. This morning I came across an excellent example of the kind of thing that we’re trying to counter.

In the current issue of Linux Format, there’s an article about building a Twitter client in the bash shell. It’s written by Nick Veitch – who seems to dislike Perl a bit. In the article he wants to URL encode a string and can’t find an easy way to do it in bash. He writes:

However, the compromise I’ve found for this isn’t too bad (props to http://stakface.com/nuggets). It uses Perl and, like everything in that language, it looks like you ought to sacrifice a goat or something before you run it.

perl -p -e 's/([^A-Za-z0-9.-~])/sprintf("%%%02X", ord($1))/seg'

It’s not clear to me which part of the Perl make him want to start sacrificing goats. Is it the s/// syntax that Perl borrowed from sed? Perhaps it’s the regular expression syntax that Perl shares with pretty much any language with regex support. Or maybe it’s the sprintf function that Perl borrowed from C and that many other languages (including bash) support with a pretty similar syntax.

Of course I’m not saying that Perl doesn’t have some grungy corners in its syntax. But the three pieces of syntax used in this code fragment look to me like things that should be understood easily by just about anyone with experience of programming in the Unix environment.

And if this code is so hard to understand, why use it? I don’t know what Nick’s programming language of choice is, but couldn’t you do exactly the same thing in Python, Ruby or PHP? I can’t believe that Perl is the only language that is so powerful. And I’d be very surprised if the same code didn’t look very similar in many other languages.

So why the unnecessary little dig at Perl?

Of course, it’s clear that Perl isn’t a language that Nick is particularly familiar with (neither, indeed, is the person who he took the solution from). Anyone who knew Perl would realise that Perl’s standard distribution includes the CGI module which contains an escape function which does exactly what Nick wanted – without exposing the programmer to all of that scary syntax. I would write Nick’s code something like this:

perl -MCGI=escape -e'print escape "@ARGV"'

There are a lot of people out there with really strange ideas about Perl. People who don’t bother to find out the best ways to do things in Perl. And having widely-read Linux magazines printing snide comments about Perl does no-one any good at all.

This is why I think that Perl marketing is important. We need to reach the people outside of the echo chamber and tell them that Perl isn’t the outdated, hard-to-use language that they are being told that it is.

Update: I should have pointed out that I’ve sent an abbreviated version of this to Linux Format. Hopefully it’ll be published in the next issue. And I’m considering proposing a series of articles on Perl to them.