| use crate::io; |
| use crate::path::Path; |
| use crate::task::spawn_blocking; |
| use crate::utils::Context as _; |
| |
| /// Reads the entire contents of a file as raw bytes. |
| /// |
| /// This is a convenience function for reading entire files. It pre-allocates a buffer based on the |
| /// file size when available, so it is typically faster than manually opening a file and reading |
| /// from it. |
| /// |
| /// If you want to read the contents as a string, use [`read_to_string`] instead. |
| /// |
| /// This function is an async version of [`std::fs::read`]. |
| /// |
| /// [`read_to_string`]: fn.read_to_string.html |
| /// [`std::fs::read`]: https://doc.rust-lang.org/std/fs/fn.read.html |
| /// |
| /// # Errors |
| /// |
| /// An error will be returned in the following situations: |
| /// |
| /// * `path` does not point to an existing file. |
| /// * The current process lacks permissions to read the file. |
| /// * Some other I/O error occurred. |
| /// |
| /// # Examples |
| /// |
| /// ```no_run |
| /// # fn main() -> std::io::Result<()> { async_std::task::block_on(async { |
| /// # |
| /// use async_std::fs; |
| /// |
| /// let contents = fs::read("a.txt").await?; |
| /// # |
| /// # Ok(()) }) } |
| /// ``` |
| pub async fn read<P: AsRef<Path>>(path: P) -> io::Result<Vec<u8>> { |
| let path = path.as_ref().to_owned(); |
| spawn_blocking(move || { |
| std::fs::read(&path).context(|| format!("could not read file `{}`", path.display())) |
| }) |
| .await |
| } |
