src/test/ui-fulldeps/switch-stdout.rs

   1 // run-pass
   2
   3 use std::env;
   4 use std::fs::File;
   5 use std::io::{Read, Write};
   6 use std::path::PathBuf;
   7
   8 #[cfg(unix)]
   9 fn switch_stdout_to(file: File) {
  10     use std::os::unix::prelude::*;
  11
  12     extern "C" {
  13         fn dup2(old: i32, new: i32) -> i32;
  14     }
  15
  16     unsafe {
  17         assert_eq!(dup2(file.as_raw_fd(), 1), 1);
  18     }
  19 }
  20
  21 #[cfg(windows)]
  22 fn switch_stdout_to(file: File) {
  23     use std::os::windows::prelude::*;
  24
  25     extern "system" {
  26         fn SetStdHandle(nStdHandle: u32, handle: *mut u8) -> i32;
  27     }
  28
  29     const STD_OUTPUT_HANDLE: u32 = (-11i32) as u32;
  30
  31     unsafe {
  32         let rc = SetStdHandle(STD_OUTPUT_HANDLE, file.into_raw_handle() as *mut _);
  33         assert!(rc != 0);
  34     }
  35 }
  36
  37 fn main() {
  38     let path = PathBuf::from(env::var_os("RUST_TEST_TMPDIR").unwrap());
  39     let path = path.join("switch-stdout-output");
  40     let f = File::create(&path).unwrap();
  41
  42     println!("foo");
  43     std::io::stdout().flush().unwrap();
  44     switch_stdout_to(f);
  45     println!("bar");
  46     std::io::stdout().flush().unwrap();
  47
  48     let mut contents = String::new();
  49     File::open(&path).unwrap().read_to_string(&mut contents).unwrap();
  50     assert_eq!(contents, "bar\n");
  51 }