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 File
s 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 writeto
. - Some other I/O error occurred.
Examples
use async_std::fs;
let num_bytes = fs::copy("a.txt", "b.txt").await?;