pub fn stderr() -> Stderr ⓘ
Expand description
Constructs a new handle to the standard error of the current process.
This handle is not buffered.
§Note: Windows Portability Considerations
When operating in a console, the Windows implementation of this stream does not support non-UTF-8 byte sequences. Attempting to write bytes that are not valid UTF-8 will return an error.
In a process with a detached console, such as one using
#![windows_subsystem = "windows"]
, or in a child process spawned from such a process,
the contained handle will be null. In such cases, the standard library’s Read
and
Write
will do nothing and silently succeed. All other I/O operations, via the
standard library or via raw Windows API calls, will fail.
§Examples
Using implicit synchronization:
use std::io::{self, Write};
fn main() -> io::Result<()> {
io::stderr().write_all(b"hello world")?;
Ok(())
}
RunUsing explicit synchronization:
use std::io::{self, Write};
fn main() -> io::Result<()> {
let stderr = io::stderr();
let mut handle = stderr.lock();
handle.write_all(b"hello world")?;
Ok(())
}
Run