Merge #774

774: #602 added unistd::mkfifo r=asomers a=jpastuszek

Since libc has mkfifo already I have just copied mkdir and adapted to mkfifo. I have tested that on MacOS only.

CHANGELOG.md

@@ -34,6 +34,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
   ([#773](https://github.com/nix-rust/nix/pull/773))
 - Add nix::sys::fallocate
   ([#768](https:://github.com/nix-rust/nix/pull/768))
+- Added `nix::unistd::mkfifo`.
+  ([#602](https://github.com/nix-rust/nix/pull/774))
 
 ### Changed
 - Renamed existing `ptrace` wrappers to encourage namespacing ([#692](https://github.com/nix-rust/nix/pull/692))

src/unistd.rs

@@ -438,6 +438,49 @@ pub fn mkdir<P: ?Sized + NixPath>(path: &P, mode: Mode) -> Result<()> {
     Errno::result(res).map(drop)
 }
 
+/// Creates new fifo special file (named pipe) with path `path` and access rights `mode`.
+///
+/// # Errors
+///
+/// There are several situations where mkfifo might fail:
+///
+/// - current user has insufficient rights in the parent directory
+/// - the path already exists
+/// - the path name is too long (longer than `PATH_MAX`, usually 4096 on linux, 1024 on OS X)
+///
+/// For a full list consult
+/// [posix specification](http://pubs.opengroup.org/onlinepubs/9699919799/functions/mkfifo.html)
+///
+/// # Example
+///
+/// ```rust
+/// extern crate tempdir;
+/// extern crate nix;
+///
+/// use nix::unistd;
+/// use nix::sys::stat;
+/// use tempdir::TempDir;
+///
+/// fn main() {
+///     let tmp_dir = TempDir::new("test_fifo").unwrap();
+///     let fifo_path = tmp_dir.path().join("foo.pipe");
+/// 
+///     // create new fifo and give read, write and execute rights to the owner
+///     match unistd::mkfifo(&fifo_path, stat::S_IRWXU) {
+///        Ok(_) => println!("created {:?}", fifo_path),
+///        Err(err) => println!("Error creating fifo: {}", err),
+///     }
+/// }
+/// ```
+#[inline]
+pub fn mkfifo<P: ?Sized + NixPath>(path: &P, mode: Mode) -> Result<()> {
+    let res = try!(path.with_nix_path(|cstr| {
+        unsafe { libc::mkfifo(cstr.as_ptr(), mode.bits() as mode_t) }
+    }));
+
+    Errno::result(res).map(drop)
+}
+
 /// Returns the current directory as a PathBuf
 ///
 /// Err is returned if the current user doesn't have the permission to read or search a component

test/test_unistd.rs

@@ -85,6 +85,24 @@ fn test_mkstemp_directory() {
     assert!(mkstemp(&env::temp_dir()).is_err());
 }
 
+#[test]
+fn test_mkfifo() {
+    let tempdir = TempDir::new("nix-test_mkfifo").unwrap();
+    let mkfifo_fifo = tempdir.path().join("mkfifo_fifo");
+
+    mkfifo(&mkfifo_fifo, stat::S_IRUSR).unwrap();
+
+    let stats = stat::stat(&mkfifo_fifo).unwrap();
+    let typ = stat::SFlag::from_bits_truncate(stats.st_mode);
+    assert!(typ == stat::S_IFIFO); 
+}
+
+#[test]
+fn test_mkfifo_directory() {
+    // mkfifo should fail if a directory is given
+    assert!(mkfifo(&env::temp_dir(), stat::S_IRUSR).is_err());
+}
+
 #[test]
 fn test_getpid() {
     let pid: ::libc::pid_t = getpid().into();