mr - tape manual recovery - Cache-A system script

#!/bin/bash
# Recovers current tape in to $data_location (directory) and logs activity to $log_location (file)
# If an argument is given, this is the blocking factor

cont_loop=""
block_size="300"
serial=$(tapeinfo -rf /dev/nst0 -mam | grep "User Medium Text Label:" | awk '{ print $NF }')
log_location="/media/manual_tar.log"
data_location="/media/vtape/manual_recovery/"
count=0

mkdir -p $data_location
chmod 777 $data_location

if [ $# -ge 1 ];
then
    block_size="$1"
fi

echo "Rewinding ..."
mt -f /dev/nst0 rewind

echo -e "Recovery of tape $serial started" | tee -a $log_location;

while true;
do
    count=$(expr $count + 1)
    cont_loop=$(tail -n4 $log_location | egrep "^tar: At beginning of tape, quitting now$")
    if [ -z "$cont_loop" ];
    then
        echo "Tar session $count - $(date +"%D %k:%M") - $serial" | tee -a $log_location
        tar xvf /dev/nst0 -b $block_size -C $data_location 2>&1 | tee -a $log_location
    else
        echo -e "Recovery of tape $serial finished\n\n\n" | tee -a $log_location
        exit 0
    fi
done