[X-Unix] shell script - online or not?

[Charles Howse]

On Jun 2, 2006, at 11:54 AM, Wing Wong wrote:

> On 6/2/06, Charles Howse <chowse at charter.net> wrote:
>
>> What might I be doing wrong?
>
> Short answer? Ping's error output needs to be redirected to  
> standard out:
>
> ping ..... 2>&1 | grep ....
>
> Also need to take into account when the logfile doesn't exist.
>
> Longer answer:
>
> In your code, the data tested and the data written would not be the
> same since you are trying to run the same test again when you write to
> the file. Included below is a variation of your script. You can change
> the logfile value at the start of the script instead of having to
> change every instance of it throughout the script.
>
> Tail command using the short parameter version.
>
> Ping's output redirected.
>
> Logfile presence checked beforehand.
>
>
> #!/bin/sh
> host=24.159.64.20
> logfile=ping_results.txt
>
> if [ ! -f $logfile ]; then
>      echo "$logfile either doesn't exist or isn't a file! Please  
> check!"
>      exit 1
> fi
>
> test=`ping -c 5 $host 2>&1 | grep packets`
> look=`tail -1 ping_results.txt`
>
> if [ "$test" == "$look" ] ; then
>        :
> else
>        echo >> $logfile
>        date >> $logfile
>        echo "$test" >> $logfile
> fi
>
> exit 0

That works fine, thanks very much!

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