cdbmake isn't making anything for me

I have a seven-line text file named mailboxes that contains this data:

grumpy
happy
sneezy
bashful
sleepy
dopey
doc

I want to translate that list into a constant database file.  

http://cr.yp.to/cdb/cdbmake.html tells me to execute a:

     cdbmake f ftmp

command to generate the cdb file.  When I execute a:

     cdbmake mailboxes mtemp

command, the cursor moves to a new line and nothing happens.  

Thinking I might have a permissions problem, I executed this command as root using explicit paths:

     /usr/local/bin/cdbmake /home/peter/mailboxes /home/peter/mtemp

and the no-result result was the same.  

What am I doing wrong?