I have a cron that runs a php page.
The php page is designed to log into an email account, download and import emails into the database.
This all works but sometimes, the attachments are so big, that it takes longer than the interval I allocated on the cron (15mins)
When this happens, the server starts to slow down. lengthening the time doesn't help, I would need to write something to see if this php page is already running.
If it isn't running -> run the php page
If it is running -> exit
Is there any code I can add to my php page which would enforce only one instance of this page being run?