For most technical writers, writing code was never part of our job description. Often programming skills aren't relevant enough to our jobs to justify the investment. However, a bit of Perl knowledge can go a long way, especially if you spend a great deal of time converting documents across formats, or automating your documentation process.
The power of the Perl language (at least for writers) is its ability to handle regular expressions. You can perform some crazy wildcard searches. For example, if you need to find all instances of <p class=[whatever]> and replace it with <p>, and then wrap the entire file in updated template code, Perl is the tool for the job.
Add a simple loop to the code, and you can process a thousand HTML files in seconds.
"But can't I just do a global search and replace from my HTML editor?" No, not exactly. The real benefit of Perl is that you can combine multiple search and replace options into a single script. That script ensures that the same operations are performed every time. There is no room for error. The benefits are much like those offered by the industrial revolution; the process is completely automated and your results are more consistent.
You could make a huge checklist and tediously search and replace until you caught everything.
Or you could write a single script to do the job, and pass that script to other writers. The combined benefits are huge. These "batch" operations can seriously boost your team's productivity, especially for very large projects.
Perl isn't the easiest language to learn. In fact, the regular expression syntax is a bit mind boggling at first. However, you only need to learn a little bit of the language to seriously automate tedious technical writing tasks.
If you are thinking about adding some programming skills to your resume, Perl is a great place to start.