... or there is an optimization which reduces operation cost to single
stat() call in case file is unmodified?
Please provide a reference link of some kind.
closed as off-topic by Ward, mdpc, Andrew Schulman, faker, Jenny D Apr 19 '15 at 9:59
This question appears to be off-topic. The users who voted to close gave these specific reasons:
Just read the docs yourself, it's listed in there: