Gfilui

Setup:

I use my notebook in two locations. At each location, the computer receives an IP address via DHCP. This IP address depends on the location, but is constant for each location over time. Furthermore, at each location there is a printer.

Task:

I configured both printers and would like to set the default printer according to the IP. To this purpose, I wrote a script and put it under /etc/network/if-up.d/set-default-printer, using lpoptions -d to actually set the default printer.

Script:

#!/bin/sh

ip_A="1.1.1.1"
ip_B="2.2.2.2"

pr_A="Printer-A"
pr_B="Printer-B"


ip=$(hostname -I | cut -d " " -f 1)

if [ $ip = $ip_A ]; then 
 lpoptions -d $pr_A
 touch /home/user/A
fi

if [ $ip = $ip_B ]; then 
 lpoptions -d $pr_B
 touch /home/user/B
fi

Problem:

Unfortunately, the default printer is not changed by the script (can be checked via lpoptions without further arguments).

Further diagnostics:

1. The script works when I either paste the content to or just call it from the command line.


2. The script is executed by the if-up-mechanism, which is verified by the creation of files /home/user/(A|B).


3. In particular, following from 1 or 2, the script file itself is executable.

Apparently, the lpoptions needs to be executed as the local user. Hence, replacing

lpoptions -d $pr

by

sudo -H -u user lpoptions -d $pr

for both printers $pr solves the problem.

Assuming, user is your user name, the complete script /etc/network/if-up.d/set-default-printer is now:

#!/bin/sh

ip_A="1.1.1.1"
ip_B="2.2.2.2"

pr_A="Printer-A"
pr_B="Printer-B"


ip=$(hostname -I | cut -d " " -f 1)

if [ $ip = $ip_A ]; then 
 sudo -H -u user lpoptions -d $pr_A
fi

if [ $ip = $ip_B ]; then 
 sudo -H -u user lpoptions -d $pr_B
fi