Re: Behavior of lseek() on a fd opened with 'RDONLY' flag, when seekinggoes beyond file size.

From: David Newall
Date: Tue Jun 17 2008 - 10:30:28 EST


palani saravanan wrote:
> In linux, I see that it just goes beyond the file size and returns the resulting offset.
> For example, 'rc = lseek(fd, 4L, SEEK_END);' on a file which has 5 byte contents,
> it returns rc as 9.
>

Sounds right. It's documented that way, too:

"The lseek() function allows the file offset to be set beyond the
end of the file (but this
does not change the size of the file)."
-- man 2 lseek
> I expect that it would return size of the file, i.e.) 5.
>

Only if you pass (0,SEEK_END).

> Does the file pointer internally really points to the new location.?
>

So the documentation promises.
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