1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
13 // Previously libstd would set stdio descriptors of a child process
14 // by `dup`ing the requested descriptors to inherit directly into the
15 // stdio descriptors. This, however, would incorrectly handle cases
16 // where the descriptors to inherit were already stdio descriptors.
17 // This test checks to avoid that regression.
19 #![cfg_attr(unix, feature(libc))]
20 #![cfg_attr(windows, allow(unused_imports))]
26 use std::io::{Read, Write};
27 use std::io::{stdout, stderr};
28 use std::process::{Command, Stdio};
31 use std::os::unix::io::FromRawFd;
35 // Bug not present in Windows
40 let mut args = std::env::args();
41 let name = args.next().unwrap();
42 let args: Vec<String> = args.collect();
43 if let Some("--child") = args.get(0).map(|s| &**s) {
45 } else if !args.is_empty() {
46 panic!("unknown options");
49 let stdout_backup = unsafe { libc::dup(libc::STDOUT_FILENO) };
50 let stderr_backup = unsafe { libc::dup(libc::STDERR_FILENO) };
51 assert!(stdout_backup > -1);
52 assert!(stderr_backup > -1);
54 let (stdout_reader, stdout_writer) = pipe();
55 let (stderr_reader, stderr_writer) = pipe();
56 assert!(unsafe { libc::dup2(stdout_writer, libc::STDOUT_FILENO) } > -1);
57 assert!(unsafe { libc::dup2(stderr_writer, libc::STDERR_FILENO) } > -1);
59 // Make sure we close any duplicates of the writer end of the pipe,
60 // otherwise we can get stuck reading from the pipe which has open
61 // writers but no one supplying any input
62 assert_eq!(unsafe { libc::close(stdout_writer) }, 0);
63 assert_eq!(unsafe { libc::close(stderr_writer) }, 0);
65 stdout().write_all("parent stdout\n".as_bytes()).expect("failed to write to stdout");
66 stderr().write_all("parent stderr\n".as_bytes()).expect("failed to write to stderr");
71 .stdin(Stdio::inherit())
72 .stdout(unsafe { Stdio::from_raw_fd(libc::STDERR_FILENO) })
73 .stderr(unsafe { Stdio::from_raw_fd(libc::STDOUT_FILENO) })
77 // The Stdio passed into the Command took over (and closed) std{out, err}
78 // so we should restore them as they were.
79 assert!(unsafe { libc::dup2(stdout_backup, libc::STDOUT_FILENO) } > -1);
80 assert!(unsafe { libc::dup2(stderr_backup, libc::STDERR_FILENO) } > -1);
82 // Using File as a shim around the descriptor
83 let mut read = String::new();
84 let mut f: File = unsafe { FromRawFd::from_raw_fd(stdout_reader) };
85 f.read_to_string(&mut read).expect("failed to read from stdout file");
86 assert_eq!(read, "parent stdout\nchild stderr\n");
88 // Using File as a shim around the descriptor
90 let mut f: File = unsafe { FromRawFd::from_raw_fd(stderr_reader) };
91 f.read_to_string(&mut read).expect("failed to read from stderr file");
92 assert_eq!(read, "parent stderr\nchild stdout\n");
94 assert!(child.expect("failed to execute child process").wait().unwrap().success());
99 stdout().write_all("child stdout\n".as_bytes()).expect("child failed to write to stdout");
100 stderr().write_all("child stderr\n".as_bytes()).expect("child failed to write to stderr");
104 /// Returns a pipe (reader, writer combo)
105 fn pipe() -> (i32, i32) {
106 let mut fds = [0; 2];
107 assert_eq!(unsafe { libc::pipe(fds.as_mut_ptr()) }, 0);