Mapping stat(1) device number/name to partition?

[Jeremy Chadwick]

On Wed, Mar 05, 2008 at 11:07:28AM +0100, Rick van der Zwet wrote:
> Hi all,
> 
> I am looking for a way to detect the file system a certain file lives
> and next whether this file system is mounted/accessible as writable. [1]
> 
> As stat(1) is helping me out to found out the proper device name/number
> of a certain file with the command `stat -f "%d" /etc/motd`, but next
> will be the mapping from this device number (st_dev) to the proper
> partion/mount point.
> 
> Which handy shell utility program will help me doing this?

fstat(1) sounds like it might be of help here.  If you're writing a C
program for this, the source code is in src/usr.bin/fstat.

> [1] Part of getting rid of the annoying motd update failure message,
>     when /etc is not writable. I know setting update_motd=NO in
>     /etc/rc.conf will do the trick as well, but I would like to see him
>     detecting it auto-magically ;-)

I haven't seen the "auto-updating motd" feature of FreeBSD since the 3.x
days.  Are you referring to the "annoyance" where during mergemaster(1),
you can nuke your /etc/motd?  If so, try IGNORE_MOTD=yes in
/etc/mergemaster.rc.

-- 
| Jeremy Chadwick                                    jdc at parodius.com |
| Parodius Networking                           http://www.parodius.com/ |
| UNIX Systems Administrator                      Mountain View, CA, USA |
| Making life hard for others since 1977.                  PGP: 4BD6C0CB |