updating file times

Bill Hawes (whawes@star.net)
Sun, 11 Jan 1998 15:11:37 -0500

I'm planning to review the various filesystems' handling of atime,
mtime, and ctime, but haven't been able to find the relevant standards
defining how these are supposed to be treated. The Unix 98 docs only
specify when the values should be changed, but don't state what actions
should result in updates.

Does POSIX spell out how and when a file's times should be changed? I'm
a little fuzzy on some of the details, such as whether a write should
change ctime if the file's length changes, or whether atime should be
updated for a read satisfied entirely by the page cache.

Any pointers to online docs would be appreciated ...

Regards,
Bill