#!/bin/bash

USER=$1
GROUP=$2

USER_GROUPS=$(id -Gn "$USER" 2>/dev/null)

IFS=' '

read -ra ADDR <<< "$USER_GROUPS"

function result () {
for i in "${ADDR[@]}"; do 
    if [ $i = $GROUP ]; then
        return 1        
    fi    
done
}

result
echo $?
