UNIX for Dummies Questions & Answers

Hi,

I would like to know about the usage of brackets to negate a set of boolean evaluations
an equivalent to what i am trying is below

if [ ! [ [$INPUT=="Morning"] or [$INPUT=="Evening"] || [$INPUT=="Night"] ] ]
then
echo"valid time of day"
else
echo "invalid input"
exit
fi

the bracket structue as mentioned doesnt work .. i am using ksh. Please help.
Thanks a dozen. hoping for a quick reply .

The below code works

if ! (( [ ${TIME_OF_DAY} = "MORNING" ] ) || ( [ ${TIME_OF_DAY} = "AFTERNOON" ]) || ([ ${TIME_OF_DAY} = "EVENING" ] ) || ( [ ${TIME_OF_DAY} = "NIGHT" ]))

Thanks

Code:

if [[ $input != @(Morning|Evening|Night) ]] ; then
        echo fumble
fi

Look at http://www.tldp.org/LDP/abs/html/tests.html
This is for bash, but I think it is also appropriate for ksh (At leas this gives good understanding of tests in shell scripts)

Thanks Guys. I got the idea .