CODEWITHSUNDEEP
linuxbashloopsif-statement
Huckleberry Finn
Huckleberry Finn

Reputation: 159

Bash continue only if ping is down

I'm trying to create a script which will only continue when pinging is unresponsive.

I'm running into 2 main issues. One being that it will require 2 CTL-C commands to end the script, and the other issue being that the script will never end and will need killing.

Here are my attempts;

rc=0
until [ $rc -gt 0 ]
do
      ping 69.69.69.69 > /dev/null 2>&1
      rc=$?
done

## Here will be the rest of code to be executed

I feel this one above is very close as it requires the 2 CTL-C commands and continues. Here is something I found on SO but can't get to work at all.

counter=0
while [ true ]
do
  ping -c 1 69.69.69.69 > /dev/null 2>&1
    if [ $? -ne 0 ] then
        let "counter +=1"
    else
        let "counter = 0"
    fi
    if [ $counter -eq 10 ] then
        echo "Here should be executed once pinging is down"
    fi
done

Any assistance is greatly appreciated, Thank you.

Upvotes: 0

Views: 3555

Answers (2)

louigi600
louigi600

Reputation: 743

There's a few issues with that: Firstly the if statements are wrong Use this format 

if [ $? -ne 0 ] then;

or this other format

if [ $? -ne 0 ]
then

Secondly I suspect that your pings are not timing out

ping -c 1 -w 2 69.69.69.69 > /dev/null 2>&1

might be helpfull

Thirdly your loop will continue incrementing counter even after 10. You might want to quit after 10

while [ $counter -le 10 ]

If you would be happy with executing something if ping times out after x seconds without any response it could be all condensed (ten seconds in the example below):

ping -c 1 -w 10 69.69.69.69 >/dev/null 2>&1 || echo "run if ping timedout without any response"

Upvotes: 1

Alfe
Alfe

Reputation: 59416

Try this:

while ping -c 1 -W 20 "$host" >& /dev/null
do
  echo "Host reachable"
  sleep 10  # do not ping too often
done
echo "Host unreachable within 20 seconds"

Upvotes: 3

Related Questions