how to know that a new file is added in a folder using php -

how to know that a new file is added in a folder using php -

i have folder called pdf user upload pdf's in it,i want php script run every 5 minutes read pdf folder in order check newly added files in folder?and intimate admin few files next file names added,how can using php

php scripts cannot auto execute execute if there request made them..

a simple thought in case pe

1.write php function logic see if filesystem has changed , necessary

action(email/database update) on execution.

place & phone call function on home page(index.php).

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