Setting up external compare tools

You can use an external compare tool as the default compare editor.

About this task

Engineering Workflow Management includes sample templates for several popular compare tools that you can use to automatically resolve conflicts. You can customize these templates for different environments. If a template does not exist for a compare tool, you can use the custom template to define one.

Note: Not all compare tools are appropriate for use as an auto-resolve merge tool. Check the compare tool documentation and the command line reference to determine whether the tool can automatically resolve conflicts.

A compare tool must exit with appropriate return codes. A zero return code indicates a successful auto-resolve and a nonzero return code indicates that conflicts cannot be automatically resolved. The compare tool must also support three-way compare scenarios.

In the Eclipse and Visual Studio clients, you can view and configure the auto-resolve templates on the External Compare Tools preferences page. For the CLI client, set the external.merge scm property either by running &ldquoscm set pref external.merge value&rdquo or by editing the file.

You can run &ldquoscm list preferences -v&rdquo to display sample values for the external.merge property. Also, the file includes examples of external.merge settings for popular merge tools.


  1. Click Window > Preferences.
  2. In the Preferences dialog box, go to Team > Jazz Source Control > External Compare Tools.
  3. On the External Compare Tools page, complete the following steps:
    1. Below Use an External Tool for Compare, select an option.
    2. In the External Compare Tool to Use field, select a compare editor.
    3. Edit the 2-Way Compare and 3-Way Conflict Compare fields.
      Tip: If you click in an arguments field, content assist (Ctrl+Space) is available to describe the arguments.
  4. Optional: To use an external merge tool to automatically resolve conflicts during certain source control operations, such as accept and resume, below Use an External Tool for Auto-Resolve, select an option. Add arguments to the Auto-resolve Arguments field.
  5. Click Apply.