꿈

# cat marummo.sh

if [ $# -ne 1 ]
then
        echo 'usage: marummo n (number)'
        exit
fi

c1=1

lines=$(($1*2-1))

echo total lines: $lines

while [ $c1 -le $lines ]
do
        c2=1

        while [ $c2 -le $lines ]
        do

                if ( [ $c1 -le $1 ] && [ $c2 -ge $(($1-($c1-1))) ] && [ $c2 -le $(($1+($c1-1))) ] ) || ( [ ! $c1 -le $1 ] && [ $c2 -ge $(($1-($lines-$c1))) ] && [ $c2 -le $(($1+($lines-$c1))) ] )
                then
                        echo -n "*"

                else
                        echo -n " "
                fi
                c2=$((c2+1))
        done

        echo
        c1=$((c1+1))
done