How to schedule dynamic function with cron job?

Question

I want to know how I can schedule a dynamic(auto populated data) function to auto run everyday at saved time? Let's say I have a form that once the button is clicked it sends the data to the function, which the posts the data. I simply want to automate that so that I don't have to press the button. ```

``` Now, the form will pass the data to the function. ``` if(isset($_POST['post_data'])) // if post_data button is clicked then it runs myFunction() { myFunction(); } myFunction() { $name = $_POST['name']; $description = $_POST['description']; } ``` I tried doing the following but the problem is that Cron Job can only run the whole .php file, and I am retrieving the saved time to run from MySQL. ``` f…

Accepted Answer

you have 2 ways, although only one will do exactly what you want to do;

1st way requires that you have access and privileges to change cron-jobs server side (example via PHP or other). Depending on what OS there are tutorials: Win , Nix

2nd way will do something close to what you want but without the minutes precision, you will loose at max 2 minutes each cycle. (see exaplanation below).

1st Way perfect way

- As soon as the user hit the form create a unique cron-task for that user using the desired datatime.

if you don't have those privileges you can use 3d part service like www.easycron.com they also offer a Free version with limited query. they also provide a REST API method to manage (CRUDE) cron-tasks.

2nd Way imperfect way

- add a new `VARCHAR` column, i called it `today` with this we will ensure that the task will run only once per day.

```
+----+---------+----------+------------+--------+----------+
| iD | timeDay | timeHour | timeMinute | postiD |   today  |
+--------------------------------------+--------+----------+
| 1  | *       | 9        | 0          | 21     | 30-05-04 |
|----|---------|----------|------------|--------|----------+
| 2  | *       | 10       | 30         | 22     |          |
|----|---------|----------|------------|--------|----------+
| 3  | *       | 11       | 0          | 23     |          |
+----|---------+----------+------------+--------+----------+
```

after that create a php file i called it `crontask.php` we will call it each 5 minutes

add this to your cronjob panel:

`0,5 * * * * /usr/bin/php /www/virtual/username/crontask.php > /dev/null 2>&1`

in the `crontask.php` file

```
<?php
// include() Database Config file here with mysql_connect etc...
// include() the required files ex. the file where myFunction reside...

$cron_cycle = 5; // set it equal to what used in cron command-line
$today = date('Y-m-d');
if($result = mysql_query("SELECT * FROM postDataTime WHERE today != '{$today}'")){
    while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) { 
        $postID = $row['postID'];
        $timeHour = (int) $row['timeHour'];
        $current_hours = (int) date('H'); // current hours
        $current_minutes = (int) date('i'); // current minutes
        $timeMinute = (int) $row['timeMinute'];
        // force to run at the closest cycle
        $timeMinute = ($timeMinute % $cycle === 0) ? $timeMinute : toCloser($timeMinute, $cron_cycle); 
        if( $current_hours === $timeHour && $current_minutes === $timeMinute ){
            // ensure that we have already runned a cron for this user...
            mysql_query("UPDATE postDataTime SET today = '{$today}' WHERE postID = '{$postID}'");
            myFunction($postID);
        }
    }
}
function toCloser($n,$x=5) {
    $j = (round($n)%$x === 0) ? round($n) : (round(($n+$x/2)/$x)*$x);
    return ($j-$n) >= round($x/2) ? ($j-$x) : $j;
}

?>
```

Explanation of the function:

Assuming that the cron shedule runs each 5 minutes, lat's say we are at 20:00 o'clock, now the cron will run at 20:05, 20:10, 20:15, 20:20 and so on...

then assuming in our DB we have those time

```
Jonh  : 20:05, 
Mario : 20:32, 
luke  : 20:48, 
David : 20:57, 
Jimmy : 20:06, 
Eddy  : 20:16
```

when the script checks against those times it will run as below:

```
at 20:05 -> run 20:05 Jonh, 20:06 Jimmy
at 20:10 -> run null
at 20:15 -> run 20:16 Eddy
at 20:20 -> run null
and so on....
```

As you see you would loose in the worst case 2 minutes each time. I think it's fair enough! ;)

How to schedule dynamic function with cron job?

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