Trait std::io::Seek

pub trait Seek {
    fn seek(&mut self, pos: SeekFrom) -> Result<u64>;

The Seek trait provides a cursor which can be moved within a stream of bytes.

The stream typically has a fixed size, allowing seeking relative to either end or the current offset.


Files implement Seek:

use std::io;
use std::io::prelude::*;
use std::fs::File;
use std::io::SeekFrom;

fn main() -> io::Result<()> {
    let mut f = File::open("foo.txt")?;

    // move the cursor 42 bytes from the start of the file

Required Methods

Seek to an offset, in bytes, in a stream.

A seek beyond the end of a stream is allowed, but implementation defined.

If the seek operation completed successfully, this method returns the new position from the start of the stream. That position can be used later with SeekFrom::Start.


Seeking to a negative offset is considered an error.


impl Seek for File [src]

impl<'a> Seek for &'a File [src]

impl<'a, S: Seek + ?Sized> Seek for &'a mut S [src]

impl<R: Seek> Seek for BufReader<R> [src]

Seek to an offset, in bytes, in the underlying reader.

The position used for seeking with SeekFrom::Current(_) is the position the underlying reader would be at if the BufReader had no internal buffer.

Seeking always discards the internal buffer, even if the seek position would otherwise fall within it. This guarantees that calling .into_inner() immediately after a seek yields the underlying reader at the same position.

To seek without discarding the internal buffer, use [Seek::seek_relative].

See [std::io::Seek] for more details.

Note: In the edge case where you're seeking with SeekFrom::Current(n) where n minus the internal buffer length overflows an i64, two seeks will be performed instead of one. If the second seek returns Err, the underlying reader will be left at the same position it would have if you called seek with SeekFrom::Current(0).

impl<S: Seek + ?Sized> Seek for Box<S> [src]

impl<T> Seek for Cursor<T> where
    T: AsRef<[u8]>, 

impl<W: Write + Seek> Seek for BufWriter<W> [src]

Seek to the offset, in bytes, in the underlying writer.

Seeking always writes out the internal buffer before seeking.

© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.