[Dovecot] Trying to modify the source - fopen problems

[Phillip T. George]

Hello all,

I don't know if this needs to be sent to a different list or not, if so, 
please let me know.

Anyways, I'm trying to modify the dovecot source a bit, but the problem 
I'm having is that whenever I use "fopen", it always returns NULL.  I've 
tried a variety of things, even fopen("/dev/null", "w") -- because that 
should almost always work.  I'm trying to get it to work in 
src/pop3-login/client-authenticate.c

Any idea why this might be happening?  Any suggestions as to where to 
put the code instead?  (I'm trying to check the username against some 
information in a file OR pass the username to a process and have it do 
the work)

Thanks,
Phillip