bash shell script syntax error [duplicate]

Answer 1

I would use extended test constructs (BASH) as demonstrated bellow. I think it would reduce the no of characters and increase readability (at least for programmers). :-)

addem() { 
        if (( $# == 0 || $# > 2 )) 
        then 
                echo -1 
        elif (( $# == 1 )) 
        then 
                echo (( $1 + $1 )) 
        else 
                echo (( $1 + $2 ))
        fi 
 }