I am fairly new to creating server scripts and jobs that the server runs every day.
My problem is as follow:
I want to send an email to my users reminding them of a specific job they have to do.
My idea:
Database -> collect all users who needs to be notified and insert them into a table notify_user
Script -> find all users and send them a mail
Script -> Delete all from the table
This script will then run at a specific time every day for instance every 24th hour.
As I stated earlier I am not really keen on how to setup such a script.
My server is an Ubuntu server and my application is a PHP program.
Does anyone know how I might achieve this or know where I might find some documentation on this subject since I have been unable to find anything that solves this issue.
If given that you know how to populate the 'notify_user' table then these are my steps to reproduce a solution sample for you. I did this on my VPS server with sendmail daemon running.
# mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 167
Server version: 5.5.40-0ubuntu0.14.04.1 (Ubuntu)
Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> create database stack_mail_db;
Query OK, 1 row affec`enter code here`ted (0.05 sec)
mysql> grant all privileges on stack_mail_db.* to 'stack_mail_usr'@'localhost' identified by 'stack_mail_pass';
Query OK, 0 rows affected (0.11 sec)
mysql> use stack_mail_db;
Database changed
mysql> create table notify_user( id int not null auto_increment primary key, user_name tinytext, user_email tinytext );
Query OK, 0 rows affected (0.28 sec)
After creating this sample database we should populate it with at least 2 users (for testing) with working emails. I changed here the actual emails I used.
mysql> insert notify_user (user_name, user_email) values ('test1', 'test1@test.com');
Query OK, 1 row affected (0.18 sec)
mysql> insert notify_user (user_name, user_email) values ('test2', 'test2@test.net');
Query OK, 1 row affected (0.03 sec)
Now we should write a script that gets these details and sends emails:
# vim cron_email.php
<?php
$host = 'localhost';
$user = 'stack_mail_usr';
$pass = 'stack_mail_pass';
$dbname = 'stack_mail_db';
$conn = new mysqli($host, $user, $pass, $dbname);
if ($conn->connect_error) {
trigger_error('DB connection failed: ' . $conn->connect_error, E_USER_ERROR);
}
$query = 'select * from notify_user';
$res = $conn->query($query);
if ($res === false) {
trigger_error('Failed query: ' . $query . ' Error: ' . $conn->error, E_USER_ERROR);
}
$headers = 'From: admin@example.com' . "\r\n" .
'Reply-To: admin@example.com' . "\r\n" .
'X-Mailer: PHP/' . phpversion();
$res->data_seek(0);
while ($row = $res->fetch_assoc()) {
$to = $row['user_email'];
$subject = 'Notification for ' . $row['user_name'];
$message = 'Hello ' . $row['user_name'];
$mail = mail($to, $subject, $message, $headers);
if ($mail) {
$conn->query('delete from notify_user where id=' . $row['id']);
} else {
echo "Email failed\n";
}
}
Now it's time to put this script on cron:
# crontab -e
0 0 * * * php -f /path/to/cron_email.php
This will run your script exactly every midnight. If you want to set a more specific hour, look at this tutorial: http://www.cyberciti.biz/faq/how-do-i-add-jobs-to-cron-under-linux-or-unix-oses/
Hope this helps ^)