Add a wrapper for lutimes(2)

CHANGELOG.md

@@ -18,7 +18,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
   ([#916](https://github.com/nix-rust/nix/pull/916))
 - Added `kmod` module that allows loading and unloading kernel modules on Linux.
   ([#930](https://github.com/nix-rust/nix/pull/930))
-- Added `futimens` and `utimesat` wrappers ([#944](https://github.com/nix-rust/nix/pull/944))
+- Added `futimens` and `utimesat` wrappers ([#944](https://github.com/nix-rust/nix/pull/944)),
+  an `lutimes` wrapper ([#967](https://github.com/nix-rust/nix/pull/967)),
   and a `utimes` wrapper ([#946](https://github.com/nix-rust/nix/pull/946)).
 - Added `AF_UNSPEC` wrapper to `AddressFamily` ([#948](https://github.com/nix-rust/nix/pull/948))
 - Added the `mode_t` public alias within `sys::stat`.

src/sys/stat.rs

@@ -199,6 +199,26 @@ pub fn utimes<P: ?Sized + NixPath>(path: &P, atime: &TimeVal, mtime: &TimeVal) -
     Errno::result(res).map(|_| ())
 }
 
+/// Change the access and modification times of a file without following symlinks.
+///
+/// `lutimes(path, times)` is identical to
+/// `utimensat(None, path, times, UtimensatFlags::NoFollowSymlink)`. The former
+/// is a deprecated API so prefer using the latter if the platforms you care
+/// about support it.
+///
+/// # References
+///
+/// [lutimes(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/lutimes.html).
+#[cfg(not(target_os = "android"))]
+pub fn lutimes<P: ?Sized + NixPath>(path: &P, atime: &TimeVal, mtime: &TimeVal) -> Result<()> {
+    let times: [libc::timeval; 2] = [*atime.as_ref(), *mtime.as_ref()];
+    let res = path.with_nix_path(|cstr| unsafe {
+        libc::lutimes(cstr.as_ptr(), &times[0])
+    })?;
+
+    Errno::result(res).map(|_| ())
+}
+
 /// Change the access and modification times of the file specified by a file descriptor.
 ///
 /// # References

test/test_stat.rs

@@ -6,7 +6,7 @@ use std::time::{Duration, UNIX_EPOCH};
 use libc::{S_IFMT, S_IFLNK};
 
 use nix::fcntl;
-use nix::sys::stat::{self, fchmod, fchmodat, fstat, futimens, lstat, stat, utimes, utimensat};
+use nix::sys::stat::{self, fchmod, fchmodat, fstat, futimens, lstat, lutimes, stat, utimes, utimensat};
 use nix::sys::stat::{FileStat, Mode, FchmodatFlags, UtimensatFlags};
 use nix::sys::time::{TimeSpec, TimeVal, TimeValLike};
 use nix::unistd::chdir;
@@ -178,6 +178,25 @@ fn test_utimes() {
     assert_times_eq(9990, 5550, &fs::metadata(&fullpath).unwrap());
 }
 
+#[test]
+fn test_lutimes() {
+    let tempdir = tempfile::tempdir().unwrap();
+    let target = tempdir.path().join("target");
+    let fullpath = tempdir.path().join("symlink");
+    drop(File::create(&target).unwrap());
+    symlink(&target, &fullpath).unwrap();
+
+    let exp_target_metadata = fs::symlink_metadata(&target).unwrap();
+    lutimes(&fullpath, &TimeVal::seconds(4560), &TimeVal::seconds(1230)).unwrap();
+    assert_times_eq(4560, 1230, &fs::symlink_metadata(&fullpath).unwrap());
+
+    let target_metadata = fs::symlink_metadata(&target).unwrap();
+    assert_eq!(exp_target_metadata.accessed().unwrap(), target_metadata.accessed().unwrap(),
+               "atime of symlink target was unexpectedly modified");
+    assert_eq!(exp_target_metadata.modified().unwrap(), target_metadata.modified().unwrap(),
+               "mtime of symlink target was unexpectedly modified");
+}
+
 #[test]
 fn test_futimens() {
     let tempdir = tempfile::tempdir().unwrap();