IO#seek with SEEK_SET

ruby-talk
1

Does calling IO#seek on a file with the SEEK_SET option internally do
something efficient if the position I want to seek to is ahead of the
current position? Or does it always do a rewind and then seek?

martin

2

Hi,

···

In message "Re: IO#seek with SEEK_SET" on Sat, 19 Feb 2005 19:39:44 +0900, Martin DeMello <martindemello@yahoo.com> writes:

Does calling IO#seek on a file with the SEEK_SET option internally do
something efficient if the position I want to seek to is ahead of the
current position? Or does it always do a rewind and then seek?

It uses fseek(3) internally, so it's probably doing "something
efficient", rather than "rewind then seek".

              matz.

3

Hi,

···

Am Samstag, 19. Feb 2005, 19:39:44 +0900 schrieb Martin DeMello:

Does calling IO#seek on a file with the SEEK_SET option internally do
something efficient if the position I want to seek to is ahead of the
current position? Or does it always do a rewind and then seek?

That depends on what you operation system's `lseek' call
does.

I would be wondering if the hard disks read head
moved the way you describe.

Bertram

--
Bertram Scharpf
Stuttgart, Deutschland/Germany
http://www.bertram-scharpf.de

4

Good point.

martin

···

Bertram Scharpf <lists@bertram-scharpf.de> wrote:

I would be wondering if the hard disks read head
moved the way you describe.