Invoking "kcheckpass" from the terminal


I'm looking for help with debugging the kcheckpass program that is used for
validating passwords in the KDE screenlocker.

It seems to me that the best method for this would be to invoke "kcheckpass"
directly in the terminal under GDB so that its interaction with my system's
PAM module could be inspected.

The executable is available... "locate kcheckpass" leads me right to it.
However, after trying several invocations, I can't get the tool to behave as
expected (i.e., take a password on stdin and exit with 0/1 on success/

Is there someone available who can help me understand how to manually invoke
this program for debugging purposes?