bash isn't a language so much as a command interpreter that's been hacked to death to allow for things that make it look like a scripting language. It's great for the simplest 1-5 line one-off tasks, but things that are dead simple in Perl or Python like array manipulation are horribly ugly in bash. I also find that bash tends not to pass two critical rules of thumb:
The 6-month rule, which says you should be able to easily discern the purpose and basic mechanics of a script you wrote but haven't looked at in 6 months.
The 'WTF per minute' rule. Everyone has their limit, and mine is pretty small. Once I get to 3 WTFs/min, I'm looking elsewhere.
As for 'shelling out' in scripting languages like Perl and Python, I find that I almost never need to do this, fwiw (disclaimer: I code almost 100% in Python). The Python os and shutil modules have most of what I need most of the time, and there are built-in modules for handling tarfiles, gzip files, zip files, etc. There's a glob module, an fnmatch module... there's a lot of stuff there. If you come across something you need to parallelize, then indent your code a level, put it in a 'run()' method, put that in a class that extends either threading.Thread or multiprocessing.Process, instantiate as many of those as you want, calling 'start()' on each one. Less than 5 minutes to get parallel execution generally.
Best of luck. Hope this helps.
