What action updates a file's ACCESS time?

[Boyd Roberts]

In article <893 at jonlab.UUCP> jon at jonlab.UUCP (Jon H. LaBadie) writes:
>In article <331 at twg.bc.ca> bill at twg.bc.ca (Bill Irwin) writes:
>>I would like to know ALL the possible activities that could result in a file's
>>access  time (ls -lu) being updated.
>

Reading the data in the file update its access time.

>Note also that write's to a file require a read first.  You may want to
>write one character.  But disks transfer data in blocks.  Thus, to
>write your one character, the block it will be written in must be read
>into memory.  You will "write" your one character into that memory
>buffer and the entire block will be written to disk.
>
>Thus writes also update access times.
>

No, that read is not always neccessary.  If the write spans the block no read
is neccessary.  Should a read be necessary, the read happens invisibly in that
the access time is not changed.  That read is not a true access of the file.
It's a side affect of the file-system implementation.


Boyd Roberts			boyd at necisa.ho.necisa.oz.au

``When the going gets wierd, the weird turn pro...''