For importing source code in clear case we need run below command it will import whole source code directory in clearcase recursively .
clearfsimport -follow -r -nsetevent soucrce_code_directory vob-direcory
This above command will do following operation:
1. checkout the parent directory
2. checkout that element in that directory and check in that element.
3. Check in that directory as well once all file element has been imported
4. follow option that symbolic link as well and make it clearcase element.
5. nsetevent will mention the time stamp of that elements.
For getting more option please see man page of clearfsimport .