On 4/7/06, Stuart Sears <stuart@xxxxxxxxxxx> wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Dan Track wrote: > > On 4/7/06, Paul Howarth <paul@xxxxxxxxxxxx> 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
