Does the Mediawiki extension SyntaxHighlight GeSHi come with highlighting support for bash/ash/sh, for example by coloring program arguments, strings and numbers or emphasizing commands? Example (this is SO highlighting for bash):
user@host ~/test $ ls "abc"
abc
Or is there some (generic) language definition which covers some of it?
Yes.
gives:
Note that the highlighter changed in recent versions of the extension.