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[Dan Track]

On 4/7/06, Stuart Sears <stuart at sjsears.com> wrote:
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> Dan Track wrote:
> > On 4/7/06, Paul Howarth <paul at city-fan.org> wrote:
> >> Dan Track wrote:
> >>> Hi
> >>>
> >>> Simple question, I'm running a command `command`, what I'd like to do
> >>> is check to see if the response is empty then exit. Does anyone know
> >>> how I can perform that check?
> >> Exit if "command" produces no output:
> >> [ -z "$(command)" ] && exit
> >>
> >> Paul.
> >
> > Hi
> >
> > Incidentally. What do you have $() instead of just ().
>
> $(command) == `command`
>
> otherwise you would be testing the length of the literal string '(command)'
>
> this way we are running command and testing the length of its output.
>
> Regards
>
> Stuart
> - --

Hi
Thanks for that. Although never having used it I thought "(command)"
meant execute the command in a child shell. I thought the pranthesis
represented anew shell. I take it I'm definitely wrong. If I am wrong
then what is the difference between (command)=="" and `command`==""

Thanks again
Dan