I've never been able to figure this out. In vi, how do you do global substitions across a file? :s/a/b/g does a substitution across the line, but not the file.

sed would probably be better to accomplish that task.

Specify the range of lines you want affected. If you don't, it assumes current line only. Some examples:

:%s/foo/bar/ -- substitute across the entire file
:.,$s/foo/bar/ -- substitute on this line and all lines through to the end of the file
:10,.s/foo/bar -- from line 10 to the current line (dot).
:'a,'bs/foo/bar/ -- from mark a to mark b

You can also do arithmetic expressions. I often find myself doing :.,.+10s/.../---/ to get this line and the ten following it. Arithmetic should work on any of the above expressions (though it doesn't make much sense to add to $, which is end of file anyway). You could do $-10 to get until 10 lines shy of end-of-file.

Ah, it was the '%' that I needed. I used to know that, but I had forgotten.

Thanks! :)