tokio-fs: How can I get file position like Python's file.tell()?

[ariesdevil]

How can I get a file position like Python's file.tell()? Does the seek API can do same thing?

[Darksonn]

The seek method returns the position after seeking, so you can seek by zero like this:

use tokio::io::AsyncSeekExt;
use std::io::SeekFrom;

let pos = file.seek(SeekFrom::Current(0)).await?;
println!("Current position in file is {}.", pos);

[ariesdevil]

It seems seek op will cause a syscall?

[Darksonn]

Yes it does. Note that Python's tell() probably also causes a syscall. You can of course also manually keep track of the position with an integer.

[ariesdevil]

Got it, thx