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Old 11-25-2011, 06:29 AM   #1
Flowsen
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[solved] ifconfig without output when used in shellscript during startup


Hello,

i have a shellscript, let it call "returnip.sh"
Inside this script, various IP adresses are stored into variables:

Code:
                ETH0=`/sbin/ifconfig eth0 2> /dev/null | egrep -o ". inet Adresse:[0-9]+.?[0-9]+.?[0-9]+.?[0-9]+." | cut -d: -f2 2> /dev/null`
                WLAN0=`/sbin/ifconfig wlan0 2> /dev/null | egrep -o ". inet Adresse:[0-9]+.?[0-9]+.?[0-9]+.?[0-9]+." | cut -d: -f2 2> /dev/null`
                TUN0=`/sbin/ifconfig tun0 2> /dev/null | egrep -o ". inet Adresse:[0-9]+.?[0-9]+.?[0-9]+.?[0-9]+." | cut -d: -f2 2> /dev/null`
                PPP0=`/sbin/ifconfig ppp0 2> /dev/null | egrep -o ". inet Adresse:[0-9]+.?[0-9]+.?[0-9]+.?[0-9]+." | cut -d: -f2 2> /dev/null`
This works fine as long as i run the script from shell. If I start the script using runlevel during startup the script runs but the variables are empty.
All interaces are up at this time so there must be another reason why /sbin/ifconfig returs no value. Could someone please help me?

Thank you.

Last edited by Flowsen; 11-25-2011 at 08:41 AM.
 
Old 11-25-2011, 07:15 AM   #2
unSpawn
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Is at startup only a limited shell available? (I mean ash, dash, nash, etc, etc and not BaSH.)
Does the script run with root rights?
What shows if you run the script but only save the output to a file for troubleshooting purposes? Is it still empty?
BTW why run ifconfig four times when you can output to a temporary file once and grep that four times?
 
Old 11-25-2011, 07:38 AM   #3
jhwilliams
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Quote:
Originally Posted by unSpawn View Post
BTW why run ifconfig four times when you can output to a temporary file once and grep that four times?
Eh, I agree that the script needs work, but that doesn't sound much better. Surely some Bash 4.0 or Awk magic to do it one fell swoop?
 
Old 11-25-2011, 07:44 AM   #4
Flowsen
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Thanks for the reply.
Yes indeed, this could be shortend to execute ifconfig just one time...

Quote:
Is at startup only a limited shell available? (I mean ash, dash, nash, etc, etc and not BaSH.)
Well I think bash is availible because the scripts is running in the background and acting as it should. It checks incomming SMS from a huawei UMTS stick.
Once it gets the SMS, it checks for command, executes and sends back a sms. Everything is working fine except the output varibles ETH0, WLAN0... are empty. It is running as root because reboot command per SMS etc. work fine.


BTW
Code:
                FILES=`ls -A /home/inbox/*${SMSNUMMER}* 2> /dev/null`
this part of the script works just fine

Code:
                ETH0=`/sbin/ifconfig`
still stays empty

Last edited by Flowsen; 11-25-2011 at 08:12 AM.
 
Old 11-25-2011, 08:45 AM   #5
Flowsen
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I solved the problem:
Code:
                if [ $ETH0 ]; then
                        STATUS="LAN:$ETH0\n"
                fi
After changing this if case it works now, Just wondering why it worked running the script from shell......
 
Old 11-27-2011, 06:57 PM   #6
unSpawn
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Quote:
Originally Posted by Flowsen View Post
it works now
...because now it only checks exit value. You could have written '/bin/false || STATUS="LAN:$ETH0\n";' and it would equally be of no value ;-p
 
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