A more elegant way of obtaining a name of a character device by its file
descriptor on FreeBSD, is to use the FIODGNAME ioctl. Because a valid
file descriptor implies a file descriptor is visible in /dev, it will
always resolve a valid device name.
I'm adding a more friendly wrapper for this ioctl, called fdevname(). It
is a lot easier to use than devname() and also has better error
handling. When a device name cannot be resolved, it will just return
NULL instead of a generated device name that makes no sense.
Discussed with: kib
were not present when dev_mkdb(8) was run.
First the dev_mkdb(8) database is searched, this caters for non-DEVFS
cases where people have renamed a device.
If that fails we ask the kernel using sysctl kern.devname if the device
driver has put a name in the dev_t. This covers DEVFS cloned devices.
If that also fails we format a string which isn't entirely useless.
(devname() returned "??" when the lookup failed, but callers expected it
to return NULL). This was fixed in Lite2, but until recently the changes
were only merged into devname.3. A day or two after devname.c was fixed,
devname.3 was made inconsistent again by backing out most of the Lite2
changes.
track.
The $Id$ line is normally at the bottom of the main comment block in the
man page, separated from the rest of the manpage by an empty comment,
like so;
.\" $Id$
.\"
If the immediately preceding comment is a @(#) format ID marker than the
the $Id$ will line up underneath it with no intervening blank lines.
Otherwise, an additional blank line is inserted.
Approved by: bde
