条件语句练习2

#!/bin/sbin
path=/server/scripts
[ ! -d "$path"] && mkdir $path -p

#menu
cat <<END        1.[install lamp]
        2.[install lnmp]
        3.[exit]
        pls input the num your want:

END
read num
expr $num + 1 &>/dev/null
[ $? -ne 0 ] &&{
        echo "the num you input must be {1|2|3}"
        exit 1
}

[ $num == "1" ] &&{
        echo "start installing lamp..."
        sleep 2;
        [ -x "$path/lamp.sh" ] ||{
            echo "$path/lamp.sh does not exist or can not be exec."
            exit 1
        }
        source $path/lamp.sh
        exit $?
}

[ $num == "2" ] &&{
        echo "start installing lnmp..."
        sleep 2;
        [ -x "$path/lnmp.sh" ] ||{
            echo "$path/lnmp.sh dose not exist or can not be exec."
            exit 1
        }
        source $path/lnmp.sh
        exit #?
}

[ $num -eq "3" ] &&{
        echo "bye."
        exit 3
}

[[ ! $num =~ [1-3] ]] &&{
        echo "the num you input must be {1|2|3}"
        echo "input error!"
        exit 4
}