IO#seek with SEEK_SET

[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?

martin

 

[Yukihiro Matsumoto]

Hi,

In message "Re: IO#seek with SEEK_SET"

|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.

 

[Bertram Scharpf]

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

 

[Martin DeMello]

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

Good point.

martin