• DBIx::Class (and Rose::DB)
• BioPerl (and related technology)
• Catalyst
• Template (and Mason)
• Moose (arguably #1 though not usually specifically mentioned in job posts)
• Not explicitly Perl but seen on job boards in tandem constantly-
  • Testing and QA stuff
  • Sysadmin and deployment stuff
  • DBA stuff
• Encode
• JSON
• XML::LibXML
• DateTime

Your question is open-ended but if you have solid chops in a good amount of those you will find quite a few jobs are available. I listed them in roughly the density they have in my automatic job emails. I recommend something like http://indeed.com's automated mailers. They are highly tweakable.

Update: meant to say: you'll need to whittle down what you want to learn to specifics if you want pointers/links/tutorials.

If you are looking for a Perl based job and need to update your knowledge, what you should study?

In my experience, to get a Perl job, most of the time you need something else. For the past 15 years, I've used Perl in my job in one form or another. In only one job, I was an actual Perl developer (but I was hired for knowing more than just Perl); for the rest, Perl was just an important tool. Saying "I want a Perl job" sounds to be "I want a job where I can drive a car". There are lots of jobs that involve driving cars. But for most of them, having a driving license isn't the only (or the most important) requirement for the job. Nor is the job advertised as "driving a car".

++.

For the OP and others: I think this is a very sober answer. Most job posts for Java, C, sysadmin, and to a lesser degree things like DBA and business analyst put Perl in the "nice to have" list. It can facilitate just about any computer oriented work flow. The first four jobs in which I used Perl were not primarily Perl jobs at all; including graphic design and customer service. I have drifted into full blown (web-oriented) Perl jobs just because I like Perl so well and because every time my job's ratio of Perl has increased my pay has too. :)

As soon as they adopt an alphabet with a sane number of graphemes I might. If I were born in China even basic school kid's comics magazines would be out of my reach. IMNSHO the chinese alphabet was one of the main reasons of Chinese stagnation in comparison to Europe. It efectively prevented the invention and spread of book printing. There's simply way too many graphemes for this to be feasible.

Jenda
Enoch was right!
Enjoy the last years of Rome.

Korea is a good example of this problem. They had no writing system of their own 600 years ago. They used Chinese idiograms. Their illiteracy rate was enormous. In the middle of the 1400s court scholars at the direction of the king developed a simple, purely phonetic alphabet for Korean. Today it contains, 24 letters, IIRC, and can be learned by a non-native in a day or two, making phonetic reading fairly simple. The CIA says China's literacy rate is 90% and Korea's is 98%. And frankly I think the definition of literacy here gives China tremendous benefit of doubt. A Korean who can read, can read *all* Korean words, even if they are unfamiliar. A Chinese person who can read at a basic literacy level would probably find most of the uncommon/scholarly idiograms unintelligible.

Sidenote: I find Chinese writing incredibly beautiful.

May I ask for more background? Who are you? I don't mean your name, although you might well grab a robe. I mean to ask who you are relative to your career. Are you just starting out? Switching careers? Moving up? What do you want to do? What kind of work? Sysadmin? Webwizard? Gamemaster? Maintenance is less glamorous than development but there's considerable demand. When do you want to get paid? Weekly paycheck? End-of-contract lump sum? Multiple tiny rivers of donations? Where do you want to work? IBM? Save The Whales? Canonical? Your living room? How do you learn best? Some hit the books, some go to school, some hack and hack and hack and hack and hack until they get it. Most important: Why write Perl, or for that matter, any code? Almost by definition, software is highly portable, which means you can always be replaced by somebody living in the cornfields or on the other side of the world; no matter where you live or how cheaply you work, there's always somebody who'll work cheaper. Nursing is a much more durable career.

I can think of many good answers to all of these questions but they're not your answers. I wouldn't try to suggest anything to you without knowing more. I do think that by the time you've answered these (and similar) to your own satisfaction, you'll know where to look for the hard info you need.

Fair is fair and I'll answer in my own voice, just to illustrate. I'm an old hardware dog who always wrote a little code, just to make all the lights come on; I've moved on from engineering entirely and now I tutor Math. I use Perl mostly for personal amusement, although my current project is a web application that may even produce a revenue trickle. I don't expect to make much money doing this and whenever the cash comes, however little, is soon enough. I work in my own place or wherever the wifi is strong. I learn best by tackling hard stuff, building a real project, and bearing through roadblocks; also, I read everything in sight or online; plus, I ask directly when I can: I really appreciate a place like PerlMonks where there's some give and take. I took up the study of Perl because it's a real challenge. Anything to keep the old gray cells firing.

One piece of advice: Read the basics thoroughly. By "basics", I mean absolutely all the perldocs included with the standard distribution, plus the entire POD for any module you plan to use, plus every single page of Perl Best Practices (Conway, 2005). By "thoroughly", I mean that you should start anywhere, read randomly until you get the gist of the whole thing, then go back and read from start to finish, at least twice. Unless you're unusually brilliant, each reading will reveal new depth. Also, boning up will avoid peremptory look-here-dummy answers when you ask specific, dumb questions (as I have).

Oh, and bookmark PerlMonks and return daily. Spend an hour in study and meditation. The Light will come.

Browse recent SoPW questions to develop a feel for the sort of stuff people are doing, or at least are having trouble doing.

Depends on what you already know, doesn't it!

It also depends on the sort of job you want to do (if, for example, you want to work in scientific computing, BioPerl might be useful, but it's of little practical use elsewhere).

My current employer looks for people who know DBIx::Class, Catalyst and some Templatey thing, although if you're good enough and don't know them, then you're in with a good chance anyway, as it's not hard to pick up what's needed.

Probably the most important skill, and one that's hard to learn apart from on the job, is how to work with other peoples' code. I spend all day fixing, improving, and extending existing applications. You can pick this up to a certain extent by collaborating on open sores projects, but not to the same extent as you would on the job.

As to what I would study ... XS. In most jobs it's not needed that often, but when it is needed, few people know it. Also, I think it would be interesting.