54 lines
1.2 KiB
Rust
54 lines
1.2 KiB
Rust
#![cfg(any(target_family = "unix", target_family = "windows"))]
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use std::fs::File;
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use std::io::{Read, Write};
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mod common;
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#[cfg(unix)]
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fn switch_stdout_to(file: File) {
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use std::os::unix::prelude::*;
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extern "C" {
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fn dup2(old: i32, new: i32) -> i32;
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}
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unsafe {
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assert_eq!(dup2(file.as_raw_fd(), 1), 1);
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}
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}
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#[cfg(windows)]
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fn switch_stdout_to(file: File) {
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use std::os::windows::prelude::*;
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extern "system" {
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fn SetStdHandle(nStdHandle: u32, handle: *mut u8) -> i32;
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}
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const STD_OUTPUT_HANDLE: u32 = (-11i32) as u32;
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unsafe {
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let rc = SetStdHandle(STD_OUTPUT_HANDLE, file.into_raw_handle() as *mut _);
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assert!(rc != 0);
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}
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}
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#[test]
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fn switch_stdout() {
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let temp = common::tmpdir();
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let path = temp.join("switch-stdout-output");
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let f = File::create(&path).unwrap();
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let mut stdout = std::io::stdout();
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stdout.write(b"foo\n").unwrap();
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stdout.flush().unwrap();
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switch_stdout_to(f);
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stdout.write(b"bar\n").unwrap();
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stdout.flush().unwrap();
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let mut contents = String::new();
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File::open(&path).unwrap().read_to_string(&mut contents).unwrap();
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assert_eq!(contents, "bar\n");
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}
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