Creates a new user on raspbian cloning the pi user groups for this new user.

new_raspbian_user.sh

#!/bin/bash

# Creates a new user on raspbian
# cloning the pi user groups for 
# this new user.

new_user=$1
adduser "$new_user"
new_groups=`groups pi`
new_groups=${new_groups:8}
for g in $new_groups; do
  echo "Adding to $g"
  sudo usermod -a -G $g $new_user
done
echo "All groups for user: $new_user"
echo `groups $new_user`

Basic Usage:

$ chmod +x new_raspbian_user.sh  
$ ./new_raspbian_user.sh brian