- Specify the locking mechanism when attempting to "inc" or
- "msgchk" a local mail spool. Valid options are "dot",
- "fcntl", "flock", and "lockf". Of the four, dot-locking
- requires no special kernel or filesystem support, and simply
- creates a file called "FILE.lock" to indicate that "FILE" is
- locked.
+ Specify the locking mechanism when attempting to "inc"
+ a local mail spool. Valid options are "dot", "fcntl", "flock",
+ and "lockf".
+
+ Of the four, dot-locking requires no special kernel
+ or filesystem support, and simply creates a file called
+ "FILE.lock" to indicate that "FILE" is locked.
+ If LOCKDIR is specified, lock files will be created in that
+ directory. Otherwise, lock files will be created in the
+ directory where the file being locked resides.
+
+ To configure nmh for kernel locking, use one of the `flock',
+ `lockf' or `fcntl' values, each using the equally named
+ system call to perform the kernel-level locking.