rust/tests/ui-fulldeps/switch-stdout.rs
2023-01-11 09:32:08 +00:00

51 lines
1.1 KiB
Rust

// run-pass
use std::env;
use std::fs::File;
use std::io::{Read, Write};
use std::path::PathBuf;
#[cfg(unix)]
fn switch_stdout_to(file: File) {
use std::os::unix::prelude::*;
extern "C" {
fn dup2(old: i32, new: i32) -> i32;
}
unsafe {
assert_eq!(dup2(file.as_raw_fd(), 1), 1);
}
}
#[cfg(windows)]
fn switch_stdout_to(file: File) {
use std::os::windows::prelude::*;
extern "system" {
fn SetStdHandle(nStdHandle: u32, handle: *mut u8) -> i32;
}
const STD_OUTPUT_HANDLE: u32 = (-11i32) as u32;
unsafe {
let rc = SetStdHandle(STD_OUTPUT_HANDLE, file.into_raw_handle() as *mut _);
assert!(rc != 0);
}
}
fn main() {
let path = PathBuf::from(env::var_os("RUST_TEST_TMPDIR").unwrap());
let path = path.join("switch-stdout-output");
let f = File::create(&path).unwrap();
println!("foo");
std::io::stdout().flush().unwrap();
switch_stdout_to(f);
println!("bar");
std::io::stdout().flush().unwrap();
let mut contents = String::new();
File::open(&path).unwrap().read_to_string(&mut contents).unwrap();
assert_eq!(contents, "bar\n");
}