Information on configuring an external diff/merge tool can be found at:
This document describes how to configure tools based upon file suffix. A “*” can be used for the suffix to change the default tool settings.
For a listing of the arguments used to build the command line string, see James Manning’s blog:
The arguments for comparing two files or two versions of a file should be:
/t1=%6 /t2=%7 %1 %2
With this command line, “original version (%1)” will
be in the left panel and the “modified version (%2)” will
be in the right panel. If you want to limit yourself to strictly viewing, rather than
editing, the changes, add
/ro2 to the beginning of the above command
The arugments for merging two versions of a file from a common ancestor should be:
/m /r=%4 /t1=%7 /t2=%8 /t3=%6 /c=%9 %2 %3 %1
With this command line, “your changes (%2)” will be in the left panel, the “common ancestor (%3)” will be in the center panel, and “their changes (%1)” will be in the right panel. When you save your merge changes, they will be written to the “merge result (%4)” file.