Re: by default, does seq_file start() routine start at zero offset?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



  (bruce:  could you tweak your mailer to not add so much white space
to each replied line -- it makes a mess of including it in a reply.)

On Wed, 5 Aug 2009, Bruce Rowen wrote:

>
>        but i don't think that answers my question -- sure, i'll honour the
>       provided value, but what *is* that provided value by default?  in
>       every example i've seen, it seems to be clear that that example will
>       work properly only if that original start offset is zero.
>
>        the code in fs/proc/devices.c is a good example.  if that initial
>       offset was something other than zero, the output would be totally
>       screwed and miss printing some lines, no?
>
>
> Yes, screwed 8^)
>
> Consider an ordered array, If *pos != 0, you could return data using
> *pos as a simple
> byteoffset or you could use *pos as an element offset
> into your array (it's up to you).

  i'm still somewhat confused here.  in every example using a seq_file
that i've ever seen, it's *assumed* that the very first call to the
start() routine is going to pass a (*pos) value of zero, which is used
to signify the initial call to that start routine.  that *has* to be
consistent.  if it can be something other than zero for that *initial*
call, how would seq_files ever be guaranteed to work properly?

  i have a couple more questions coming shortly.

rday
--


========================================================================
Robert P. J. Day                               Waterloo, Ontario, CANADA

        Linux Consulting, Training and Annoying Kernel Pedantry.

Web page:                                          http://crashcourse.ca
Twitter:                                       http://twitter.com/rpjday
"Kernel Newbie Corner" column @ linux.com:          http://cli.gs/WG6WYX
========================================================================

[Index of Archives]     [Newbies FAQ]     [Linux Kernel Mentors]     [Linux Kernel Development]     [IETF Annouce]     [Git]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux SCSI]     [Linux ACPI]
  Powered by Linux