Rewind file offset

[Kuhl]

Hi, I am programming with C in Linux. During reading a file, I need to
rewind the file offset backwards sometimes. I learned that lseek()
function can check the offset. But I did not find a way to set the
offset. I tried using read(fd, databuf, -5), but the offset does not
go back. What's the correct way to rewind the file offset? Thanks.

 

[Kenny McCormack]

Hi, I am programming with C in Linux. During reading a file, I need to
rewind the file offset backwards sometimes. I learned that lseek()
function can check the offset. But I did not find a way to set the
offset. I tried using read(fd, databuf, -5), but the offset does not
go back. What's the correct way to rewind the file offset? Thanks.

With lseek().

 

[Martin Ambuhl]

Strange... My system's manual tells me that lseek() and read() are
POSIX (along with some other non-C standards like "SVr4" and "BSD 4.3").

And now you know why Richard <no last name> posts anonymously: to post
nonsense with no consequences. For some strange reason there are people
who deny that "troll" is appropriate for this anonymous poster who posts
garbage and snipes at those who know better C than he does.

 

[Kenny McCormack]

And now you know why Richard <no last name> posts anonymously: to post
nonsense with no consequences. For some strange reason there are people
who deny that "troll" is appropriate for this anonymous poster who posts
garbage and snipes at those who know better C than he does.

Yes. We see that you do this all the time.

But we tolerate you. It is a free country.

 

[Richard Bos]

Yes. We see that you do this all the time.

But we tolerate you.

What a pathetic little lie, Kenny.

Richard