Password Enforcing

#!/bin/bash 
export PASSENFORCINGDIR=/etc/bkp-password-enforcing

function FNTHROW() {
    echo "Gone bad. Execution aborted at Task " $1
    exit 1
}
function FNBACKUP() {
    echo BACKUP $1
    if [ -f $1 ]
    then
        mkdir -p $PASSENFORCINGDIR
        tar cf - $1 | gzip -9 > $PASSENFORCINGDIR/$(echo $1 | sed -e "s/\//_/g").$(date +"%Y-%m-%d_%H-%M_%S").tgz
    else
        FNTHROW backup
    fi
}
function FNCOMMAND() {
    echo COMMAND $1
    $1
    if [ $? -ne 0 ]
    then
        FNTHROW $1
    fi
}

function FNSED() {
    sed -i "s/^PASS_MAX_DAYS.*/PASS_MAX_DAYS 30/g"  /etc/login.defs
    sed -i "s/^PASS_MIN_DAYS.*/PASS_MIN_DAYS 1/g" /etc/login.defs
    sed -i "s/pam_pwquality.so/pam_pwquality.so remember=16 /g" /etc/pam.d/password-auth
}

FNBACKUP /etc/security/pwquality.conf
FNBACKUP /etc/login.defs
FNBACKUP /etc/pam.d/password-auth

FNCOMMAND "authconfig --passminlen=16 --update"
FNCOMMAND "authconfig --enablereqlower --update"
FNCOMMAND "authconfig --enablerequpper --update"
FNCOMMAND "authconfig --enablereqdigit --update"
FNCOMMAND "authconfig --enablereqother --update"

FNSED

echo End of execution
exit 0