This is also useful for iterating on a throw-away script - something too long to type on one line in the shell, but not significant enough to be worth saving to

This is also useful for iterating on a throw-away script - something too long to type on one line in the shell, but not significant enough to be worth saving to a file. Put it together in an unnamed buffer, and ":w !" it to the relevant interpreter (eg ":w !perl") whenever you want to run it.