Picking a MAC address for a FreedomBox

Posted Dec 8, 2012 17:24 UTC (Sat) by rahulsundaram (subscriber, #21946)
In reply to: Picking a MAC address for a FreedomBox by mathstuf
Parent article: Picking a MAC address for a FreedomBox

I have a file named 00-a-machanger in /etc/NetworkManager/dispatcher.d

#! /bin/bash

/bin/macchanger -r wlan0 2>&1 > /dev/null

That's all it takes.

Picking a MAC address for a FreedomBox

Posted Jan 21, 2013 16:52 UTC (Mon) by mcortese (guest, #52099) [Link] (3 responses)

/bin/macchanger -r wlan0 2>&1 > /dev/null

The redirection looks weird: stdout goes to null, while stderr goes to stdout! ;-)

Picking a MAC address for a FreedomBox

Posted Jan 21, 2013 19:00 UTC (Mon) by rahulsundaram (subscriber, #21946) [Link]

Use whatever redirection works for you.

Picking a MAC address for a FreedomBox

Posted Jan 22, 2013 0:32 UTC (Tue) by dlang (guest, #313) [Link] (1 responses)

that is the routine redirect combination that admins use when they don't plan to look at whatever output is generated and want it to be quiet. The result is that all output is thrown away.

Picking a MAC address for a FreedomBox

Posted Jan 22, 2013 1:04 UTC (Tue) by ABCD (subscriber, #53650) [Link]

No it isn't. command 2>&1 >/dev/null first copies fd 1 to fd 2 (thus sending stderr to where stdout is currently going), then sets fd 1 (stdout) to /dev/null. The standard "show me nothing" line is command >/dev/null 2>&1, which sets fd 1 to /dev/null, then copies fd 1 to fd 2.

To see the difference, compare the following:

$ to_stderr() { echo "$@" >&2; }
$ to_stderr test 2>&1 >/dev/null
test
$ to_stderr test >/dev/null 2>&1