This tool is based on the excellent work of lanfeust69 with the clearcase-to-git-importer and is able to import a ClearCase VOB to a Git repository (or several different repositories).

It has been tested on a ClearCase VOB with 17 years of history resulting in a Git repository with a size of ~500MB. The import time was about 2-3 days. It has also been tested on a much smaller VOB that imported in some hours.

• Without doubt lower code base quality since I'm unfamiliar with C# and I didn't bother to clean up the code (sorry).
• Supports extracting subfolders in the VOB to different Git repositories.
• Will drop useless or empty commits and labels.
• Significantly more aggressive with merging multiple ClearCase checkins to a Git commit.
• More aggressive with trying to keep the labels correct at a slight cost of the correctness of the history.
• Imports the author and date of a label.
• If labels are not matched properly then the Git tag will be annotated with a message.
• Better support for some edge cases, though there are still many unsolved ones remaining.
• Partial support for converting charset to UTF-8 in metadata. Filenames are known to not be converted properly. Non-ASCII characters in branches and labels can result in mojibake and eventual crash.
• Support for incremental imports has been dropped. It's all or nothing!
• Renaming of files is ignored and instead it leaves everything to Git to figure out.

It has only been tested with a dynamic ClearCase view. Support for thirdparties has not been tested.

• Export as much as possible using clearexport_ccase (in several parts due to memory constraints of clearexport_ccase).
• Get all elements (files and directories).
• Optionally edit these lists to exclude uninteresting stuff (or use excludes parameter, see below).
• Use GitImporter (which calls cleartool) to create (and save) a representation of the VOB.
• Import with GitImporter and git fast-import. cleartool is then used only to get the content of files. This is done repeatedly if importing to multiple Git repositories, though not more than needed.

If you're lucky you might be able to compile with this command:

C:\Windows\Microsoft.NET\Framework\v4.0.30319\csc.exe /debug /define:DEBUG /define:TRACE /r:protobuf-net.dll /out:scripts\GitImporter.exe /pdb:scripts\GitImporter *.cs

This tool must be run with Git Bash on Windows.

Please look inside the scripts folder and investigate import.sh; this is the wrapper that executes both export and import processes in one go. Also make sure to copy the gitignore file to a working directory (where you can also create a parameter file, see below) and modify it according to your needs in order to check it in automagically.

The provided import.sh will take a VOB and create several Git repositories from it, assuming all folders in the VOB are equivalent to different Git repositories.

For example, the following ClearCase VOB...

my_vob
├── somefolder/
|   └── file.txt
└── anotherfolder/
    └── file2.txt

... will be transformed to...

somefolder/
├── .git/
└── file.txt
anotherfolder/
├── .git/
└── file2.txt

When you run import.sh, the Git repositories will be created in a folder named git-import.

Since there are quite a few configuration parameters, import.sh can read their values from a configuration file called ìmport.conf in a working directory. Currently supported parameters are:

• viewTag: view tag (mandatory)
• vobTag: VOB tag (mandatory; no leading backslash required to avoid bash escaping)
• refDate : upper cutoff date for import, corresponds to Origin Date in GitImporter (default: current date)
• vobDirs : folders in VOB to import, glob expressions can be used (default: *)
• mergeDirs : if set to true, folders are merged rather than split into separate repos; in this case, vobDirs are not removed from paths in Git and prefixes can be used to manipulate the resulting paths
• prefixes : if set, prefixes are trimmed from paths in Git; NB! trimming happens after vobDirs are removed, which is the default behaviour when vobDirs contains a single folder
• labels : if set, only the specified labels are imported to Git (can be set to NONE to ignore the labels)
• branches : if set, only the specified branches are imported to Git
• excludes : a regexp to exclude additional subfolders or files from import on the fly (rather than editing import lists manually)

vobDirs, prefixes, labels and branches can also be specified as quoted space-separated list (e.g. "A B").