The default device cache file path of the lsof distribution is
one recorded in the home directory of the real UID that executes
lsof. Added to the home directory is a second path component of
the form .lsof_hostname.
This is lsof's fourth device cache file path choice, and is
usually the default. If a system-wide device cache file path was
defined when lsof was built, this fourth choice will be applied
when lsof can't find the system-wide device cache file. This is
the only time lsof uses two paths when reading the device cache
file.
The hostname part of the second component is the base name of the
executing host, as returned by gethostname(2). The base name is
defined to be the characters preceding the first `.' in the
gethostname(2) output, or all the gethostname(2) output if it
contains no `.'.
The device cache file belongs to the user ID and is readable and
writable by the user ID alone - i.e., its modes are 0600. Each
distinct real user ID on a given host that executes lsof has a
distinct device cache file. The hostname part of the path
distinguishes device cache files in an NFS-mounted home directory
into which device cache files are written from several different
hosts.
The personal device cache file path formed by this method
represents a device cache file that lsof will attempt to read,
and will attempt to write should it not exist or should its
contents be incorrect or outdated.
The -Dr option without a path name argument will inhibit the
writing of a new device cache file.
The -D? option will list the format specification for
constructing the personal device cache file. The conversions
used in the format specification are described in the 00DCACHE
file of the lsof distribution.
