log in ifup

Shell Programming and Scripting
1

I have a little script in the /etc/network/if-up.d (debian). It should do something and write the output to a log file. But it doesn't seem to work.

ifup wlan0 dosomething >> /var/log/dosomething.log

I would like to add the date to the output, can somebody help me please?
Thanks!

2

What does "doesn't seem to work" mean? What does happen? What do you want to happen?

date +"%Y-%m-%d_%H:%M:%S $(ifup wlan0 dosomething)" >> /var/log/dosomething.log
3

Hey, thanks for your help!

With your line, it just writes the date into the log file. No output of my dosomething program.

I tested my program; it works:

  • This writes the output of my program to the standard output (the terminal)
    text dosomething
  • This writes it to the log file
    text dosomething >> /var/log/dosomething.log
  • This writes it correctly to the standard output
    text date +"%Y-%m-%d_%H:%M:%S $(dosomething)"
  • This writes just the date (%Y-%m-%d_%H:%M:%S) to the log file (running as a script in /etc/network/if-up.d)
    text date +"%Y-%m-%d_%H:%M:%S $(ifup wlan0 dosomething)" >> /var/log/dosomething.log
    I don't know if my program was running.

Any idea?

4 
date=$( date +"%Y-%m-%d_%H:%M:%S" )
something=$(dosomething)
if [ -z "$something" ] 
then
   echo "dosomething produced no output" >&2
   exit 1
fi
printf "%s %s\n" "$date" "$something" >> /var/log/dosomething.log
5

Thanks but why ifup wlan0 doesn't work?

6

What does "doesn't work" mean?

What does happen?

What, exactly, did you try?

7

Well, when the connection to the wlan is there I would expect that my program is running. The program works and gives output but it looks like not with ifup.