Hey, I've written some simple bash scripts that fetch metar data and thought others might be interested.
There are basically two different sets: one that is usable within terminal and other that's meant to be run periodically (by cron or conky for instance).
First one is rather straight-forward: you type 'metar ZZZZ ZZZZ ZZZZ' in terminal and you'll get metar data for those airports.
The second script updates metar that's stored in separate file. It has two versions - one for airports, where metar is published every HH:50, other for HH:20 & HH:50. It compares the metar time stored in file to current time. If last saved metar is 12:50 and current time is 13:50, it downloads new metar. I used that script for printing data onto desktop using conky.
Additional instructions included in files.
1. script
2. script, 1. ver (HH:50 metars)
2. ver (HH:20 & 50 metars)