feature_extension_for_async_std::fs

Function copy

Source 
pub async fn copy<P, Q>(from: P, to: Q) -> Result<u64, Error>
where
    P: AsRef<Path>,
    Q: AsRef<Path>,
Expand description

Copies the contents and permissions of a file to a new location.

On success, the total number of bytes copied is returned and equals the length of the to file after this operation.

The old contents of to will be overwritten. If from and to both point to the same file, then the file will likely get truncated as a result of this operation.

If you’re working with open Files and want to copy contents through those types, use the io::copy function.

This function is an async version of std::fs::copy.

§Errors

An error will be returned in the following situations:

  • from does not point to an existing file.
  • The current process lacks permissions to read from or write to.
  • Some other I/O error occurred.

§Examples

use async_std::fs;

let num_bytes = fs::copy("a.txt", "b.txt").await?;