add support for mknodat

CHANGELOG.md

@@ -24,6 +24,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
   ([#739](https://github.com/nix-rust/nix/pull/739))
 - Added nix::sys::ptrace::detach. 
   ([#749](https://github.com/nix-rust/nix/pull/749))
+- Added nix::sys::stat::mknod
+  ([#747](https://github.com/nix-rust/nix/pull/747))
 
 ### Changed
 - Renamed existing `ptrace` wrappers to encourage namespacing ([#692](https://github.com/nix-rust/nix/pull/692))

src/sys/stat.rs

@@ -50,6 +50,19 @@ pub fn mknod<P: ?Sized + NixPath>(path: &P, kind: SFlag, perm: Mode, dev: dev_t)
     Errno::result(res).map(drop)
 }
 
+/// Create a special or ordinary file
+/// ([posix specification](http://pubs.opengroup.org/onlinepubs/9699919799/functions/mknod.html)).
+#[cfg(not(any(target_os = "ios", target_os = "macos")))]
+pub fn mknodat<P: ?Sized + NixPath>(dirfd: &RawFd, path: &P, kind: SFlag, perm: Mode, dev: dev_t) -> Result<()> {
+    let res = try!(path.with_nix_path(|cstr| {
+        unsafe {
+            libc::mknodat(*dirfd, cstr.as_ptr(), kind.bits | perm.bits() as mode_t, dev)
+        }
+    }));
+
+    Errno::result(res).map(drop)
+}
+
 #[cfg(target_os = "linux")]
 pub fn major(dev: dev_t) -> u64 {
     ((dev >> 32) & 0xfffff000) |

test/test_stat.rs

@@ -1,11 +1,12 @@
 use std::fs::File;
 use std::os::unix::fs::symlink;
 use std::os::unix::prelude::AsRawFd;
+use std::path::Path;
 
 use libc::{S_IFMT, S_IFLNK};
 
 use nix::fcntl;
-use nix::sys::stat::{self, stat, fstat, lstat};
+use nix::sys::stat::{self, stat, fstat, lstat, mknod};
 use nix::sys::stat::FileStat;
 use nix::Result;
 use tempdir::TempDir;
@@ -110,3 +111,28 @@ fn test_stat_fstat_lstat() {
     let fstat_result = fstat(link.as_raw_fd());
     assert_stat_results(fstat_result);
 }
+
+fn assert_fifo(path: &Path) {
+    let stats = stat(path).unwrap();
+    let typ = stat::SFlag::from_bits_truncate(stats.st_mode);
+    assert!(typ == stat::S_IFIFO);
+}
+
+#[test]
+fn test_mknod() {
+    let tempdir = TempDir::new("nix-test_mknodat").unwrap();
+    let mknod_fifo = tempdir.path().join("mknod");
+
+    mknod(&mknod_fifo, stat::S_IFIFO, stat::S_IRUSR, 0).unwrap();
+    assert_fifo(&mknod_fifo);
+}
+
+#[test]
+#[cfg(not(any(target_os = "ios", target_os = "macos")))]
+fn test_mknod_mknodat() {
+    let tempdir = TempDir::new("nix-test_mknodat").unwrap();
+    let mknodat_fifo = tempdir.path().join("mknodat");
+
+    stat::mknodat(&0, &mknodat_fifo, stat::S_IFIFO, stat::S_IRUSR, 0).unwrap();
+    assert_fifo(&mknodat_fifo);
+}