add support for fstatat

Author: Mic92

src/sys/stat.rs

@@ -2,10 +2,12 @@ pub use libc::dev_t;
 pub use libc::stat as FileStat;
 
 use {Errno, Result, NixPath};
-use libc::{self, mode_t};
+use libc::{self, c_int, mode_t};
 use std::mem;
 use std::os::unix::io::RawFd;
 
+pub use self::consts::*;
+
 mod ffi {
     use libc::{c_char, c_int, mode_t, dev_t};
     pub use libc::{stat, fstat, lstat};
@@ -109,3 +111,62 @@ pub fn fstat(fd: RawFd) -> Result<FileStat> {
 
     Ok(dst)
 }
+
+#[cfg(any(target_os = "linux", target_os = "android"))]
+mod consts {
+    use libc::c_int;
+
+    bitflags!(
+        flags FstatatFlag: c_int {
+            const AT_SYMLINK_NOFOLLOW = 0o000400,
+            const AT_NO_AUTOMOUNT     = 0o004000,
+            const AT_EMPTY_PATH       = 0o010000,
+        }
+    );
+}
+
+#[cfg(any(target_os = "freebsd", target_os = "dragonfly"))]
+mod consts {
+    use libc::c_int;
+
+    bitflags!(
+        flags FstatatFlag: c_int {
+            const AT_SYMLINK_NOFOLLOW = 0o1,
+        }
+    );
+}
+
+#[cfg(target_os = "openbsd")]
+mod consts {
+    use libc::c_int;
+
+    bitflags!(
+        flags FstatatFlag: c_int {
+            const AT_SYMLINK_NOFOLLOW = 0o02,
+        }
+    );
+}
+
+#[cfg(target_os = "netbsd")]
+mod consts {
+    use libc::c_int;
+
+    bitflags!(
+        flags FstatatFlag: c_int {
+            const AT_SYMLINK_NOFOLLOW = 0o1000,
+        }
+    );
+}
+
+#[cfg(any(target_os = "linux", target_os = "android", target_os = "freebsd", target_os = "dragonfly", target_os = "netbsd"))]
+pub fn fstatat<P: ?Sized + NixPath>(dirfd: RawFd, pathname: &P, f: FstatatFlag) -> Result<FileStat> {
+    let mut dst = unsafe { mem::uninitialized() };
+    let res = try!(pathname.with_nix_path(|cstr| {
+        unsafe { libc::fstatat(dirfd, cstr.as_ptr(), &mut dst as *mut FileStat, f.bits() as c_int) }
+    }));
+
+    try!(Errno::result(res));
+
+    Ok(dst)
+}
+

test/test_stat.rs

@@ -4,8 +4,8 @@ use std::os::unix::prelude::AsRawFd;
 
 use libc::{S_IFMT, S_IFLNK};
 
-use nix::sys::stat::{stat, fstat, lstat};
-
+use nix::fcntl;
+use nix::sys::stat::{self, stat, fstat, lstat};
 use nix::sys::stat::FileStat;
 use nix::Result;
 use tempdir::TempDir;
@@ -74,6 +74,22 @@ fn test_stat_and_fstat() {
     assert_stat_results(fstat_result);
 }
 
+#[cfg(any(target_os = "linux", target_os = "android", target_os = "freebsd", target_os = "dragonfly", target_os = "netbsd"))]
+#[test]
+fn test_fstatat() {
+    let tempdir = TempDir::new("nix-test_stat_and_fstat").unwrap();
+    let filename = tempdir.path().join("foo.txt");
+    File::create(&filename).unwrap();
+    let dirfd = fcntl::open(tempdir.path(),
+                            fcntl::O_PATH,
+                            stat::Mode::empty());
+
+    let result = stat::fstatat(dirfd.unwrap(),
+                               &filename,
+                               stat::FstatatFlag::empty());
+    assert_stat_results(result);
+}
+
 #[test]
 fn test_stat_fstat_lstat() {
     let tempdir = TempDir::new("nix-test_stat_fstat_lstat").unwrap();