Is there a way to define the preferred merge or diff tool under Unix?

Question

I know that you can define the preferred editor by setting the EDITOR environment variable.

My question is if there is a similar solution for setting the preferred merge or diff tool.

Answer 1

As far as I know, there isn't any universal way; it depends on which version control system you are using, e.g.:

• Mercurial uses a setting in .hgrc.
• git uses merge.tool configuration, as told in a comment.
• for svn, you specify in /etc/subversion/config.