Pre and Post script for MySQL server consistent* backup

MySql-Backup-Postscript.sh

#!/bin/bash

mysql -u <user> -p<Password> -e 'unlock tables;'

if [ $? -gt 0 ]; then
 echo "Failed running mysql unfreeze" 
 exit 1
else
 echo "success" 
 exit 0
fi

MySql-Backup-Prescript.sh

#!/bin/bash
echo ”Applying read lock and retaining the lock for 10 seconds ”
nohup mysql -u <user> -p<Password> -e 'flush tables;
flush tables;
flush tables with read lock;
set global read_only=1;
do sleep(10);' > foo.out 2> foo.err < /dev/null &

if [ $? -gt 0 ]; then
 echo "Failed freezing db" 
 exit 1
else
 echo "successfully freezed for 10 secs" 
 exit 0
fi