how to check for new packets

How can I check a connection (fsockopen) for new packets? I know I can use fgets but that retrieves the packet too, I only want to check if a new packet has arrived.

Thanks.

if (fgets) {
mail(packethasarrived);
}

:)

if (fgets) {
mail(packethasarrived);
}

:)

Thanks but in that way the specific packet disappears too, is there another way?