1use crate::io;
2use crate::path::Path;
3use crate::task::spawn_blocking;
4use crate::utils::Context as _;
5
6/// Writes a slice of bytes as the new contents of a file.
7///
8/// This function will create a file if it does not exist, and will entirely replace its contents
9/// if it does.
10///
11/// This function is an async version of [`std::fs::write`].
12///
13/// [`std::fs::write`]: https://doc.rust-lang.org/std/fs/fn.write.html
14///
15/// # Errors
16///
17/// An error will be returned in the following situations:
18///
19/// * The file's parent directory does not exist.
20/// * The current process lacks permissions to write to the file.
21/// * Some other I/O error occurred.
22///
23/// # Examples
24///
25/// ```no_run
26/// # fn main() -> std::io::Result<()> { async_std::task::block_on(async {
27/// #
28/// use async_std::fs;
29///
30/// fs::write("a.txt", b"Hello world!").await?;
31/// #
32/// # Ok(()) }) }
33/// ```
34pub async fn write<P: AsRef<Path>, C: AsRef<[u8]>>(path: P, contents: C) -> io::Result<()> {
35 let path: PathBuf = path.as_ref().to_owned();
36 let contents: Vec = contents.as_ref().to_owned();
37 spawn_blockingJoinHandle>(move || {
38 std::fs::write(&path, contents)
39 .context(|| format!("could not write to file `{}`", path.display()))
40 })
41 .await
42}
43