viewing major and minor device numbers

David Newman dnewman at
Fri Oct 25 20:40:58 UTC 2013

On 10/25/13 12:34 PM, Polytropon wrote:
> On Fri, 25 Oct 2013 12:26:31 -0700, David Newman wrote:
>> FreeBSD 9.2-RELEASE, amd64
>> To create some character special devices in a chroot environment, I've
>> previously used mknod, but now can't find the major and minor device
>> numbers.
>> The ls manpage says these numbers should be displayed in the size field.
>> However, I'm seeing only one hex value, e.g.:
>> $ ls -l /dev/null
>> crw-rw-rw-  1 root  wheel  0x13 Oct 25 12:22 /dev/null
>> So I don't know what major and minor values to feed mknod. Or is there
>> another way to do this?
> Do you have any "suspicious" ls alias or options preconfigured?
> That output looks a bit strange, it should be something like
> this (example from a host system, not from inside a jail):
> % /bin/ls -laFG /dev/null 
> crw-rw-rw-  1 root  wheel    0,  17 Oct 25 21:33 /dev/null
>                              ^   ^^
> This is the binary /bin/ls, no "shell builtin" or the like,
> called from the C shell; OS is FreeBSD 8, x86.

Even with /bin/ls, the system still returns the hex code:

# /bin/ls -laFG /dev/null
crw-rw-rw-  1 root  wheel  0x13 Oct 25 13:22 /dev/null

Two machines, both running 9.2/amd64, both return these hex codes. One
machine runs on bare metal and the other is a VM I just built. Both
machines have no aliases for ls.

This URL:

gives instructions for how to create devices in chroot environments
using devfs:

# $T is the chroot directory
mount -t devfs devfs $T/dev
# the default ruleset is immutable, so create a new one
devfs -m $T/dev ruleset 1
# only a small selection of devices should be visible
devfs -m $T/dev rule add path random unhide
devfs -m $T/dev rule add path urandom unhide
# make it so
devfs -m $T/dev rule applyset

This worked for me, and the chroot'd devices have the same hex IDs as
those in /dev.

But I'm still curious why ls displays those hex values instead of major
and minor device numbers.



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