Quickies > Mercurial > Use FileMerge for diffs

Create opendiff-w, an executable script in your path, with the following contents:

# opendiff returns immediately, without waiting for FileMerge to exit.
# Piping the output makes opendiff wait for FileMerge.
opendiff "$@" | cat

Set the following in your .hgrc file

[extensions]
hgext.extdiff = 

[extdiff]
cmd.opendiff = opendiff-w

Now you can see the diff in FileMerge by calling:

$ hg opendiff