Attempts to change the group of the file filename to group (specified by name or number). Only the superuser may change the group of a file arbitrarily; other users may change the group of a file to any group of which that user is a member.
Palauttaa TRUE onnistuessaan, muutoin FALSE.
Huomaa: This function will not work on remote files as the file to be examined must be accessible via the servers filesystem.
Huomaa: Kun safe mode on k�yt�ss�, PHP tarkistaa onko k�sitelt�vien tiedostojen/hakemistojen UID sama kuin ajettavalla skriptill�.