Hidden directories

[phonecian]

I just found two hidden directories on a workstation with a fairly new install of FC2.
/etc/.java
and
/etc/.pwd.lock

I dont know what they do. Are they legitimate FC2 directories. How can I see what is in them?
Thanks

[crackers]

/etc/.java is a legitimate directory - the Sun JVM uses that to store system-wide preferences information. You'll get that when you run java as "root" - which is the only user that can write to the /etc directory.

The other file (not a directory) I haven't a clue, but it's on every system I have. Add that fact in, plus only "root" can write to this directory, makes me feel quite confident that it's supposed to be there. Looks like it's written during installation...

[phonecian]

Thanks Crackers

[reks]

That file: /etc/.pwd.lock seem to be there on all the machines here with me -> FC2, RH all the way down to RH7.2. - Zero size file owned by root. I found it on a Solaris machine (SunOS-5.6) too! However DEC-OSF1 machines dont have it.

On my FC2 machine, the date of creation of the file matches the installation date. I did a google search for that. Found a similar thread in debian list (its there on debian machines too!), but they too were left clueless.

Wonder what that file does. Its very interesting though. I'll post the question on other lists and get back to this thread if I find any answers.

[SuperNu]

I ran a quick google search, and it looks like the file /etc/.pwd.lock is created by adduser to lock /etc/passwd so no other files write to it while adduser is.

--SN

[reks]

Thats right SuperNu.. While my googling didn't reach anywhere, I too got something, thanks to Atul Chitnis

/etc/.pwd.lock is the lock file. It is used to coordinate
modification access to the password files /etc/passwd and
/etc/shadow. lckpwdf and ulckpwdf are routines that are
used to gain modification access to the password files,
through the lock file. A process first uses lckpwdf to lock
the lock file thereby gaining exclusive rights to modify the
/etc/passwd or /etc/shadow password file. Upon completing
modifications, a process should release the lock on the lock
file via ulckpwdf. This mechanism prevents simultaneous
modification of the password files. i.e. it is a sentinel file,
never modified, only locked and unlocked as required. Think
of it as a semaphore.
Related manpage

Cheers! and thanks phonecian for that interesting question

[crackers]

Over 10 years using this OS and you still learn something new every day... gotta love it!