Wait on NetworkManager for wifi connection

[AlbertP]

Hi all,

Is it possible to wait till the wifi (TP-Link USB dongle with Atheros chip) is connected in a bash script, which starts a program that requires network access?

[xenopeek]

This may work: http://stackoverflow.com/questions/9458 ... 30#9458730

The command "ip route" will show you the active routing. I'm hoping it won't show a route for wlan until the wlan is active, but am not sure. If it works, you could do something like:

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if [ $(ip route | grep wlan0 | wc -l) != 0 ]; then
   # wlan0 found in "ip route" output
else
   # wlan0 not found in "ip route" output
fi

[remoulder]

Could you test if the wlan has an active ip as in

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ifconfig wlan0 | grep -i 'inet addr'

[AlbertP]

Thanks. Is there a way in Bash to let the script wait until the command returns something?

[xenopeek]

You can do so with an infinite while loop, for example as such (the colon after the while makes it infinite). Tests each time if the wlan0 has an IP address and if so exits the loop to continue your script. If it doesn't yet have an IP address, it sleeps for (for example) 1 second before testing again. You can make that 1 second longer if testing it so often is not needed.

Code: Select all

while : ; do
   if [ $(ifconfig wlan0 | grep -i 'inet addr' | wc -l) != 0 ]; then
      # wlan0 has IP address, exit loop
      break
   fi
   # sleep 1 second
   sleep 1
done