2

I have a shell script that has the first line (after #! /bin/sh):

IP=$(curl ifconfig.me)

Sometimes the script will execute and be done within 3 seconds other times it times out at this point in the script (I know because I use notify-send to display IP on the next line).

More often than not I will have to run the script several times in order to get it to complete (I use CTRL+C to interrupt).

I would love to be able to run the script once and if it hasn't completed within 10 seconds it exits and runs itself again, and keeps looping until it gets an exit code 0 within a 10 second time frame, or to fix the reason why it doesn't just complete the first time round.

I have seen a number of other solutions to get a timeout going but I haven't seen any instructions that make sense to me and thus haven't been able to implement them. For example this one.

I was thinking of giving the ulimit version a try since I'm now more experienced with python than I used to be but I'm not sure it makes sense to use a script to run a script.

I have tried using sleep but all I can seem to do is get it to pause running the script and thus it never completes.

The rest of the script sets rules for iptables.

GergelyPolonkai
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Oceanic_Panda
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3 Answers3

3

What you need to do is tailor the curl command you are using. There are a number of options which might help:

curl --connect-timeout 3 --max-time 10 --retry 3 ifconfig.me

This tells the curl command to timeout if the connection isn't established within 3 seconds, it will timeout if the complete data transfer takes more than 10 seconds, and it will retry 3 times. Adjust as appropriate!

There are a few other parameters you could set, check man curl as well.

emmalg
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  • Perfect got it sorted with this and then an if/else on whether the IP variable had a value to relaunch the script if it didn't. Many thanks – Oceanic_Panda Sep 17 '15 at 12:31
1

You should use the curl --max-time option. Then it will fail if it doesn't complete within a specified number of seconds.

John Zwinck
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0

You may use the timeout command from coreutils

while ! IP=$(timeout 3 curl ifconfig.me)
do
   sleep 1
done
Manuel Barbe
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  • Proper shell scripts should almost never examine `$?` directly. You are looking for `while ! IP=$(timeout 3 curl ...); do sleep 1: done` – tripleee Sep 17 '15 at 10:45
  • Thanks for the advise. Is it good practise to edit my answer according to your comment? – Manuel Barbe Sep 17 '15 at 10:50