Mounts an EncFS folder for sharing with other group members

mount_encfs.sh

#!/bin/bash
# BASH shell script for mounting an encrypted EncFS folder for
# for sharing with other user/users who are member of $GROUP
# Since EncFS runs in userland, no root privileges are needed.
# Remember to uncomment user_allow_other in /etc/fuse.conf

# It is currently configured to mount the encrypted folder:
# ~/.private
# on the unencrypted mount point (which is created upon mount):
# ~/private

#  To the extent possible under law, Bjoern Dahlgren has waived all
#  copyright and related or neighboring rights to this work.

USER=johndoe
GROUP=family
#FUSE does not seem to supprt SGID bit, elsewise an umask of 5007 would be nice
UMASK=007 # rwxrwx---
DIRNAME=private

uid=$(id -u $USER)
gid=$(getent group $GROUP | cut -d: -f 3)
#Allow UMASK of length 3 or 4
sevens=$(echo $UMASK | tr 01234567 77777777)
antiumask=$(echo "ibase=8; obase=8; $sevens - $UMASK" | bc)

if [ ! -d ./$DIRNAME ]
then
    mkdir $DIRNAME
    chmod $antiumask $DIRNAME
    encfs -o allow_other -o umask=$UMASK,gid=$gid,uid=$uid ~/.$DIRNAME ~/$DIRNAME || rmdir $DIRNAME
else
    echo The directory \"$DIRNAME\" already exists. Did nothing.
fi