Question

I wrote a function in bash script. However, it’s complaining about syntax. I really can’t see what is it….. the error message is [: missing `]’

addem() {
            if [ $# -eq 0] || [ $# -gt 2 ]
            then
                    echo -1
            elif [ $# -eq 1 ]
            then
                    echo $[ $1 + $1 ]
            else
                    echo $[ $1 + $2 ]
            fi
    }

Answer 1

You need a space before the first ]. That is:
change:
if [ $# -eq 0] || [ $# -gt 2 ]
to:
if [ $# -eq 0 ] || [ $# -gt 2 ]