[Crash-utility] How to fire crash command from extension directly

Hi, I have written crash extension(shared-object) for dumping few data structures from crash. I want to trigger standard crash command e.g. "bt", from crash extension itself. Can anyone please help me out, how can it be achieved ? I am using APIs exported by crash header file defs.h Your valuable suggestions would be helpful for me. Thanks in advance. Vivek Satpute