Please note that this API does not make any specific attempts to obey the mediawiki etiquette (http://www.mediawiki.org/wiki/API:Etiquette). This sort of API is easy and clean for something like a command line script, but if you're going to do further automation or crawling I strongly recommend using the pywikipediabot library (http://www.mediawiki.org/wiki/Manual:Pywikipediabot) which includes a very full API, has tunable throttling, and makes a more direct attempt to require a user agent string that is in line with the api etiquette.
If you just want a bash script to look things up on wikipedia, you can always use something like
If you just want a bash script to look things up on wikipedia, you can always use something like
function wp { curl "http://en.wikipedia.org/wiki/$(echo "$@" | tr ' ' '_')" | gunzip | html2text }
which will work for basic queries (needs url encoding and words to be properly capitalized).
A full api reference is here (http://en.wikipedia.org/w/api.php).