Passfilter provides you with a terminal that has certain words blacklisted. Upon entering a predefined character sequence the terminal will erase the written characters with backspace, give an error message and wait until the line is finished with enter. The use case would be to stop you from accidentally entering passwords to IRC or possibly to other hosts, which could be compromised and could be logging your entry.
This same web page works as the Darcs-repository as well.You will need libevent and openssl to build it. Example session:
% echo -n pass | md5sum 1a1dc91c907325c69271ddf0c944bc72 - % passfilter -s 1a1dc91c907325c69271ddf0c944bc72 % echo hello world hello world (now try to echo hello pass) % echo hello SCRUBB (you will need to press enter before you can enter new characters) hello %