Re: File Locking

[Randall Gellens]

The dot-lock file is created by appending ".lock" to the name of 
the file being locked.  The dot-lock file must be in the same 
directory as the file being locked.

Qpopper uses an additional file, ".user.pop" as a mutual-exclusion 
lock to prevent more than one POP session at the same time.  No 
other process should use this file.  The file also serves 
double-duty as the temp spool, when needed.