How to logically negate the return value of a command?

[Kevin O'Gorman]

or
if ping -c1 hostname ; then false; else true; fi

You may or may not want to redirect the output of ping to /dev/null



On Tue, Sep 23, 2014 at 8:34 AM, Nathan Dorfman <na at rtfm.net> wrote:

> On Mon, Sep 22, 2014 at 2:04 PM, Chris Green <cl at isbd.net> wrote:
> > However this doesn't work of course.  Is there any easy way (i.e. an
> > executable command) which will logically not the value that ping
> > returns?  I know I could write a little script that does the job but
> > if can do it without I'd be happier.
>
>
> There's probably a nicer way to do it, but this should work:
>
>     ping -c1 hostname; test "$?" -ne 0
>
> -nd.
>
> > --
> > Chris Green
>
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-- 
Kevin O'Gorman

programmer, n. an organism that transmutes caffeine into software.
Please consider the environment before printing this email.
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