visualizing multiple repositories at once with Gource

Sometimes it may be interesting to show the history of multiple projects in the same Gource animation. For instance: development activity in sub modules used by a project, multiple projects worked on by the same developers / company, or maybe different forks of a project.

There are lots of possibilities.

You can create a multiple repository visualization using the following shell commands:

1. Generate a Gource custom log files for each repository using the --output-custom-log FILE option:

   gource --output-custom-log log1.txt repo1
   gource --output-custom-log log2.txt repo2
   ...
   

2. (optional) If you want each repo to appear on a separate branch instead of merged onto each other (which might also look interesting), you can use a 'sed' regular expression to add an extra parent directory to the path of the files in each project:

   sed -i -r "s#(.+)\|#\1|/repo1#" log1.txt
   

   (note: sed -i does an in-place replacement on the file)

3. Join the logs together, and sort them numerically by the first column (the time):

   cat log1.txt log2.txt | sort -n > combined.txt
   

4. Feed result into gource:

   gource combined.txt
   

You can also add the --hide-root option to not connect the top level directories to make them look more distinct.