[lug] Bash Scripting Ping

[D. Stimits]

>     On 11/08/2020 12:48 PM Ron Wright <halsaves at gmail.com> wrote:
> 
> 
>     If you just trying to avoid the buffer from the pipe this will work:
> 
>     stdbuf -i0 -o0 -e0 ping -O -D 10.255.255.255 2>&1 \
>     | while read line
>     do
>        echo '*' $line '*'
>     done
> 
So far this one is looking like it works. I'll have to spend some time trying different edits, but think the non-buffered output piped to the while of read line is the answer. I never really thought of piping to while before, nor have I used stdbuf before, but it is something new and shiny!

>     A couple of notes:
>       1.  I did not have to use stdbuf on Fedora 33.  The ping output lines were not being buffered.
>       2.  10.255.255.255 does not exist on my network.
>       3.  You don't really need to unbuffer stdin.  So, "stdbuf -o0 -e0" should be enough.
> 
>     Ron Wright
> 
>     On Sun, Nov 8, 2020 at 5:53 PM D. Stimits < stimits at comcast.net mailto:stimits at comcast.net > wrote:
> 
>         > >         I am curious about something in bash scripting which does not seem to be particularly easy. I wanted to script "ping -O -D address" such that each line gets processed by some logic if the ping fails. Redirecting ping to a variable does not work because it only "returns" when the ping exits (each line is not an exit). Even if I were to fork and exec, the forked process would itself have the same problem.
> > 
> >         Is there some simple/clever way to process each line of a ping in bash without killing off the ping itself? My goal was to send it through some database and statistics type processing as success/failure lines occur.
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