Contents

#!/bin/bash

num=$(echo "$1" | sed 's/[\ ]//g')

if ! [[ 10#$num -ge 0 ]] 2>/dev/null || ! [[ ${#num} -gt 1 ]] ; then
    echo "false"
else
    shift 1

    len=${#num}
    is_odd=1
    sum=0

    for((t = len - 1; t >= 0; --t)) {
        digit=${num:$t:1}

        if [[ $is_odd -eq 1 ]]; then
            sum=$(( sum + $digit ))
        else
            sum=$(( $sum + ( $digit != 9 ? ( ( 2 * $digit ) % 9 ) : 9 ) ))
        fi

        is_odd=$(( ! $is_odd ))
    }

    if [[ 0 -eq $(( 0 != ( $sum % 10 ) )) ]] ; then
        echo "true"
    else
        echo "false"
    fi

fi

Version data entries

95 entries across 95 versions & 1 rubygems

Version	Path
trackler-2.2.1.180	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.179	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.178	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.177	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.176	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.175	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.174	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.173	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.172	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.171	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.170	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.169	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.167	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.166	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.165	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.164	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.163	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.162	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.161	tracks/bash/exercises/luhn/example.sh
trackler-2.2.1.160	tracks/bash/exercises/luhn/example.sh