Adding upstream version 115.7.0esr.upstream/115.7.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1407 insertions, 0 deletions

diff --git a/third_party/rust/nix/test/test_unistd.rs b/third_party/rust/nix/test/test_unistd.rs
new file mode 100644
index 0000000000..9e20f977ec
--- /dev/null
+++ b/third_party/rust/nix/test/test_unistd.rs
@@ -0,0 +1,1407 @@
+use libc::{_exit, mode_t, off_t};
+use nix::errno::Errno;
+#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
+use nix::fcntl::readlink;
+use nix::fcntl::OFlag;
+#[cfg(not(target_os = "redox"))]
+use nix::fcntl::{self, open};
+#[cfg(not(any(
+    target_os = "redox",
+    target_os = "fuchsia",
+    target_os = "haiku"
+)))]
+use nix::pty::{grantpt, posix_openpt, ptsname, unlockpt};
+#[cfg(not(target_os = "redox"))]
+use nix::sys::signal::{
+    sigaction, SaFlags, SigAction, SigHandler, SigSet, Signal,
+};
+use nix::sys::stat::{self, Mode, SFlag};
+use nix::sys::wait::*;
+use nix::unistd::ForkResult::*;
+use nix::unistd::*;
+use std::env;
+#[cfg(not(any(target_os = "fuchsia", target_os = "redox")))]
+use std::ffi::CString;
+#[cfg(not(target_os = "redox"))]
+use std::fs::DirBuilder;
+use std::fs::{self, File};
+use std::io::Write;
+use std::os::unix::prelude::*;
+#[cfg(not(any(
+    target_os = "fuchsia",
+    target_os = "redox",
+    target_os = "haiku"
+)))]
+use std::path::Path;
+use tempfile::{tempdir, tempfile};
+
+use crate::*;
+
+#[test]
+#[cfg(not(any(target_os = "netbsd")))]
+fn test_fork_and_waitpid() {
+    let _m = crate::FORK_MTX.lock();
+
+    // Safe: Child only calls `_exit`, which is signal-safe
+    match unsafe { fork() }.expect("Error: Fork Failed") {
+        Child => unsafe { _exit(0) },
+        Parent { child } => {
+            // assert that child was created and pid > 0
+            let child_raw: ::libc::pid_t = child.into();
+            assert!(child_raw > 0);
+            let wait_status = waitpid(child, None);
+            match wait_status {
+                // assert that waitpid returned correct status and the pid is the one of the child
+                Ok(WaitStatus::Exited(pid_t, _)) => assert_eq!(pid_t, child),
+
+                // panic, must never happen
+                s @ Ok(_) => {
+                    panic!("Child exited {:?}, should never happen", s)
+                }
+
+                // panic, waitpid should never fail
+                Err(s) => panic!("Error: waitpid returned Err({:?}", s),
+            }
+        }
+    }
+}
+
+#[test]
+fn test_wait() {
+    // Grab FORK_MTX so wait doesn't reap a different test's child process
+    let _m = crate::FORK_MTX.lock();
+
+    // Safe: Child only calls `_exit`, which is signal-safe
+    match unsafe { fork() }.expect("Error: Fork Failed") {
+        Child => unsafe { _exit(0) },
+        Parent { child } => {
+            let wait_status = wait();
+
+            // just assert that (any) one child returns with WaitStatus::Exited
+            assert_eq!(wait_status, Ok(WaitStatus::Exited(child, 0)));
+        }
+    }
+}
+
+#[test]
+fn test_mkstemp() {
+    let mut path = env::temp_dir();
+    path.push("nix_tempfile.XXXXXX");
+
+    let result = mkstemp(&path);
+    match result {
+        Ok((fd, path)) => {
+            close(fd).unwrap();
+            unlink(path.as_path()).unwrap();
+        }
+        Err(e) => panic!("mkstemp failed: {}", e),
+    }
+}
+
+#[test]
+fn test_mkstemp_directory() {
+    // mkstemp should fail if a directory is given
+    mkstemp(&env::temp_dir()).expect_err("assertion failed");
+}
+
+#[test]
+#[cfg(not(target_os = "redox"))]
+fn test_mkfifo() {
+    let tempdir = tempdir().unwrap();
+    let mkfifo_fifo = tempdir.path().join("mkfifo_fifo");
+
+    mkfifo(&mkfifo_fifo, Mode::S_IRUSR).unwrap();
+
+    let stats = stat::stat(&mkfifo_fifo).unwrap();
+    let typ = stat::SFlag::from_bits_truncate(stats.st_mode as mode_t);
+    assert_eq!(typ, SFlag::S_IFIFO);
+}
+
+#[test]
+#[cfg(not(target_os = "redox"))]
+fn test_mkfifo_directory() {
+    // mkfifo should fail if a directory is given
+    mkfifo(&env::temp_dir(), Mode::S_IRUSR).expect_err("assertion failed");
+}
+
+#[test]
+#[cfg(not(any(
+    target_os = "macos",
+    target_os = "ios",
+    target_os = "android",
+    target_os = "redox",
+    target_os = "haiku"
+)))]
+fn test_mkfifoat_none() {
+    let _m = crate::CWD_LOCK.read();
+
+    let tempdir = tempdir().unwrap();
+    let mkfifoat_fifo = tempdir.path().join("mkfifoat_fifo");
+
+    mkfifoat(None, &mkfifoat_fifo, Mode::S_IRUSR).unwrap();
+
+    let stats = stat::stat(&mkfifoat_fifo).unwrap();
+    let typ = stat::SFlag::from_bits_truncate(stats.st_mode);
+    assert_eq!(typ, SFlag::S_IFIFO);
+}
+
+#[test]
+#[cfg(not(any(
+    target_os = "macos",
+    target_os = "ios",
+    target_os = "android",
+    target_os = "redox",
+    target_os = "haiku"
+)))]
+fn test_mkfifoat() {
+    use nix::fcntl;
+
+    let tempdir = tempdir().unwrap();
+    let dirfd = open(tempdir.path(), OFlag::empty(), Mode::empty()).unwrap();
+    let mkfifoat_name = "mkfifoat_name";
+
+    mkfifoat(Some(dirfd), mkfifoat_name, Mode::S_IRUSR).unwrap();
+
+    let stats =
+        stat::fstatat(dirfd, mkfifoat_name, fcntl::AtFlags::empty()).unwrap();
+    let typ = stat::SFlag::from_bits_truncate(stats.st_mode);
+    assert_eq!(typ, SFlag::S_IFIFO);
+}
+
+#[test]
+#[cfg(not(any(
+    target_os = "macos",
+    target_os = "ios",
+    target_os = "android",
+    target_os = "redox",
+    target_os = "haiku"
+)))]
+fn test_mkfifoat_directory_none() {
+    let _m = crate::CWD_LOCK.read();
+
+    // mkfifoat should fail if a directory is given
+    mkfifoat(None, &env::temp_dir(), Mode::S_IRUSR)
+        .expect_err("assertion failed");
+}
+
+#[test]
+#[cfg(not(any(
+    target_os = "macos",
+    target_os = "ios",
+    target_os = "android",
+    target_os = "redox",
+    target_os = "haiku"
+)))]
+fn test_mkfifoat_directory() {
+    // mkfifoat should fail if a directory is given
+    let tempdir = tempdir().unwrap();
+    let dirfd = open(tempdir.path(), OFlag::empty(), Mode::empty()).unwrap();
+    let mkfifoat_dir = "mkfifoat_dir";
+    stat::mkdirat(dirfd, mkfifoat_dir, Mode::S_IRUSR).unwrap();
+
+    mkfifoat(Some(dirfd), mkfifoat_dir, Mode::S_IRUSR)
+        .expect_err("assertion failed");
+}
+
+#[test]
+fn test_getpid() {
+    let pid: ::libc::pid_t = getpid().into();
+    let ppid: ::libc::pid_t = getppid().into();
+    assert!(pid > 0);
+    assert!(ppid > 0);
+}
+
+#[test]
+#[cfg(not(target_os = "redox"))]
+fn test_getsid() {
+    let none_sid: ::libc::pid_t = getsid(None).unwrap().into();
+    let pid_sid: ::libc::pid_t = getsid(Some(getpid())).unwrap().into();
+    assert!(none_sid > 0);
+    assert_eq!(none_sid, pid_sid);
+}
+
+#[cfg(any(target_os = "linux", target_os = "android"))]
+mod linux_android {
+    use nix::unistd::gettid;
+
+    #[test]
+    fn test_gettid() {
+        let tid: ::libc::pid_t = gettid().into();
+        assert!(tid > 0);
+    }
+}
+
+#[test]
+// `getgroups()` and `setgroups()` do not behave as expected on Apple platforms
+#[cfg(not(any(
+    target_os = "ios",
+    target_os = "macos",
+    target_os = "redox",
+    target_os = "fuchsia",
+    target_os = "haiku"
+)))]
+fn test_setgroups() {
+    // Skip this test when not run as root as `setgroups()` requires root.
+    skip_if_not_root!("test_setgroups");
+
+    let _m = crate::GROUPS_MTX.lock();
+
+    // Save the existing groups
+    let old_groups = getgroups().unwrap();
+
+    // Set some new made up groups
+    let groups = [Gid::from_raw(123), Gid::from_raw(456)];
+    setgroups(&groups).unwrap();
+
+    let new_groups = getgroups().unwrap();
+    assert_eq!(new_groups, groups);
+
+    // Revert back to the old groups
+    setgroups(&old_groups).unwrap();
+}
+
+#[test]
+// `getgroups()` and `setgroups()` do not behave as expected on Apple platforms
+#[cfg(not(any(
+    target_os = "ios",
+    target_os = "macos",
+    target_os = "redox",
+    target_os = "fuchsia",
+    target_os = "haiku",
+    target_os = "illumos"
+)))]
+fn test_initgroups() {
+    // Skip this test when not run as root as `initgroups()` and `setgroups()`
+    // require root.
+    skip_if_not_root!("test_initgroups");
+
+    let _m = crate::GROUPS_MTX.lock();
+
+    // Save the existing groups
+    let old_groups = getgroups().unwrap();
+
+    // It doesn't matter if the root user is not called "root" or if a user
+    // called "root" doesn't exist. We are just checking that the extra,
+    // made-up group, `123`, is set.
+    // FIXME: Test the other half of initgroups' functionality: whether the
+    // groups that the user belongs to are also set.
+    let user = CString::new("root").unwrap();
+    let group = Gid::from_raw(123);
+    let group_list = getgrouplist(&user, group).unwrap();
+    assert!(group_list.contains(&group));
+
+    initgroups(&user, group).unwrap();
+
+    let new_groups = getgroups().unwrap();
+    assert_eq!(new_groups, group_list);
+
+    // Revert back to the old groups
+    setgroups(&old_groups).unwrap();
+}
+
+#[cfg(not(any(target_os = "fuchsia", target_os = "redox")))]
+macro_rules! execve_test_factory (
+    ($test_name:ident, $syscall:ident, $exe: expr $(, $pathname:expr, $flags:expr)*) => (
+
+    #[cfg(test)]
+    mod $test_name {
+    use std::ffi::CStr;
+    use super::*;
+
+    const EMPTY: &'static [u8] = b"\0";
+    const DASH_C: &'static [u8] = b"-c\0";
+    const BIGARG: &'static [u8] = b"echo nix!!! && echo foo=$foo && echo baz=$baz\0";
+    const FOO: &'static [u8] = b"foo=bar\0";
+    const BAZ: &'static [u8] = b"baz=quux\0";
+
+    fn syscall_cstr_ref() -> Result<std::convert::Infallible, nix::Error> {
+        $syscall(
+            $exe,
+            $(CString::new($pathname).unwrap().as_c_str(), )*
+            &[CStr::from_bytes_with_nul(EMPTY).unwrap(),
+              CStr::from_bytes_with_nul(DASH_C).unwrap(),
+              CStr::from_bytes_with_nul(BIGARG).unwrap()],
+            &[CStr::from_bytes_with_nul(FOO).unwrap(),
+              CStr::from_bytes_with_nul(BAZ).unwrap()]
+            $(, $flags)*)
+    }
+
+    fn syscall_cstring() -> Result<std::convert::Infallible, nix::Error> {
+        $syscall(
+            $exe,
+            $(CString::new($pathname).unwrap().as_c_str(), )*
+            &[CString::from(CStr::from_bytes_with_nul(EMPTY).unwrap()),
+              CString::from(CStr::from_bytes_with_nul(DASH_C).unwrap()),
+              CString::from(CStr::from_bytes_with_nul(BIGARG).unwrap())],
+            &[CString::from(CStr::from_bytes_with_nul(FOO).unwrap()),
+              CString::from(CStr::from_bytes_with_nul(BAZ).unwrap())]
+            $(, $flags)*)
+    }
+
+    fn common_test(syscall: fn() -> Result<std::convert::Infallible, nix::Error>) {
+        if "execveat" == stringify!($syscall) {
+            // Though undocumented, Docker's default seccomp profile seems to
+            // block this syscall.  https://github.com/nix-rust/nix/issues/1122
+            skip_if_seccomp!($test_name);
+        }
+
+        let m = crate::FORK_MTX.lock();
+        // The `exec`d process will write to `writer`, and we'll read that
+        // data from `reader`.
+        let (reader, writer) = pipe().unwrap();
+
+        // Safe: Child calls `exit`, `dup`, `close` and the provided `exec*` family function.
+        // NOTE: Technically, this makes the macro unsafe to use because you could pass anything.
+        //       The tests make sure not to do that, though.
+        match unsafe{fork()}.unwrap() {
+            Child => {
+                // Make `writer` be the stdout of the new process.
+                dup2(writer, 1).unwrap();
+                let r = syscall();
+                let _ = std::io::stderr()
+                    .write_all(format!("{:?}", r).as_bytes());
+                // Should only get here in event of error
+                unsafe{ _exit(1) };
+            },
+            Parent { child } => {
+                // Wait for the child to exit.
+                let ws = waitpid(child, None);
+                drop(m);
+                assert_eq!(ws, Ok(WaitStatus::Exited(child, 0)));
+                // Read 1024 bytes.
+                let mut buf = [0u8; 1024];
+                read(reader, &mut buf).unwrap();
+                // It should contain the things we printed using `/bin/sh`.
+                let string = String::from_utf8_lossy(&buf);
+                assert!(string.contains("nix!!!"));
+                assert!(string.contains("foo=bar"));
+                assert!(string.contains("baz=quux"));
+            }
+        }
+    }
+
+    // These tests frequently fail on musl, probably due to
+        // https://github.com/nix-rust/nix/issues/555
+    #[cfg_attr(target_env = "musl", ignore)]
+    #[test]
+    fn test_cstr_ref() {
+        common_test(syscall_cstr_ref);
+    }
+
+    // These tests frequently fail on musl, probably due to
+        // https://github.com/nix-rust/nix/issues/555
+    #[cfg_attr(target_env = "musl", ignore)]
+    #[test]
+    fn test_cstring() {
+        common_test(syscall_cstring);
+    }
+    }
+
+    )
+);
+
+cfg_if! {
+    if #[cfg(target_os = "android")] {
+        execve_test_factory!(test_execve, execve, CString::new("/system/bin/sh").unwrap().as_c_str());
+        execve_test_factory!(test_fexecve, fexecve, File::open("/system/bin/sh").unwrap().into_raw_fd());
+    } else if #[cfg(any(target_os = "dragonfly",
+                        target_os = "freebsd",
+                        target_os = "linux"))] {
+        // These tests frequently fail on musl, probably due to
+        // https://github.com/nix-rust/nix/issues/555
+        execve_test_factory!(test_execve, execve, CString::new("/bin/sh").unwrap().as_c_str());
+        execve_test_factory!(test_fexecve, fexecve, File::open("/bin/sh").unwrap().into_raw_fd());
+    } else if #[cfg(any(target_os = "illumos",
+                        target_os = "ios",
+                        target_os = "macos",
+                        target_os = "netbsd",
+                        target_os = "openbsd",
+                        target_os = "solaris"))] {
+        execve_test_factory!(test_execve, execve, CString::new("/bin/sh").unwrap().as_c_str());
+        // No fexecve() on ios, macos, NetBSD, OpenBSD.
+    }
+}
+
+#[cfg(any(target_os = "haiku", target_os = "linux", target_os = "openbsd"))]
+execve_test_factory!(test_execvpe, execvpe, &CString::new("sh").unwrap());
+
+cfg_if! {
+    if #[cfg(target_os = "android")] {
+        use nix::fcntl::AtFlags;
+        execve_test_factory!(test_execveat_empty, execveat,
+                             File::open("/system/bin/sh").unwrap().into_raw_fd(),
+                             "", AtFlags::AT_EMPTY_PATH);
+        execve_test_factory!(test_execveat_relative, execveat,
+                             File::open("/system/bin/").unwrap().into_raw_fd(),
+                             "./sh", AtFlags::empty());
+        execve_test_factory!(test_execveat_absolute, execveat,
+                             File::open("/").unwrap().into_raw_fd(),
+                             "/system/bin/sh", AtFlags::empty());
+    } else if #[cfg(all(target_os = "linux", any(target_arch ="x86_64", target_arch ="x86")))] {
+        use nix::fcntl::AtFlags;
+        execve_test_factory!(test_execveat_empty, execveat, File::open("/bin/sh").unwrap().into_raw_fd(),
+                             "", AtFlags::AT_EMPTY_PATH);
+        execve_test_factory!(test_execveat_relative, execveat, File::open("/bin/").unwrap().into_raw_fd(),
+                             "./sh", AtFlags::empty());
+        execve_test_factory!(test_execveat_absolute, execveat, File::open("/").unwrap().into_raw_fd(),
+                             "/bin/sh", AtFlags::empty());
+    }
+}
+
+#[test]
+#[cfg(not(target_os = "fuchsia"))]
+fn test_fchdir() {
+    // fchdir changes the process's cwd
+    let _dr = crate::DirRestore::new();
+
+    let tmpdir = tempdir().unwrap();
+    let tmpdir_path = tmpdir.path().canonicalize().unwrap();
+    let tmpdir_fd = File::open(&tmpdir_path).unwrap().into_raw_fd();
+
+    fchdir(tmpdir_fd).expect("assertion failed");
+    assert_eq!(getcwd().unwrap(), tmpdir_path);
+
+    close(tmpdir_fd).expect("assertion failed");
+}
+
+#[test]
+fn test_getcwd() {
+    // chdir changes the process's cwd
+    let _dr = crate::DirRestore::new();
+
+    let tmpdir = tempdir().unwrap();
+    let tmpdir_path = tmpdir.path().canonicalize().unwrap();
+    chdir(&tmpdir_path).expect("assertion failed");
+    assert_eq!(getcwd().unwrap(), tmpdir_path);
+
+    // make path 500 chars longer so that buffer doubling in getcwd
+    // kicks in.  Note: One path cannot be longer than 255 bytes
+    // (NAME_MAX) whole path cannot be longer than PATH_MAX (usually
+    // 4096 on linux, 1024 on macos)
+    let mut inner_tmp_dir = tmpdir_path;
+    for _ in 0..5 {
+        let newdir = "a".repeat(100);
+        inner_tmp_dir.push(newdir);
+        mkdir(inner_tmp_dir.as_path(), Mode::S_IRWXU)
+            .expect("assertion failed");
+    }
+    chdir(inner_tmp_dir.as_path()).expect("assertion failed");
+    assert_eq!(getcwd().unwrap(), inner_tmp_dir.as_path());
+}
+
+#[test]
+fn test_chown() {
+    // Testing for anything other than our own UID/GID is hard.
+    let uid = Some(getuid());
+    let gid = Some(getgid());
+
+    let tempdir = tempdir().unwrap();
+    let path = tempdir.path().join("file");
+    {
+        File::create(&path).unwrap();
+    }
+
+    chown(&path, uid, gid).unwrap();
+    chown(&path, uid, None).unwrap();
+    chown(&path, None, gid).unwrap();
+
+    fs::remove_file(&path).unwrap();
+    chown(&path, uid, gid).unwrap_err();
+}
+
+#[test]
+fn test_fchown() {
+    // Testing for anything other than our own UID/GID is hard.
+    let uid = Some(getuid());
+    let gid = Some(getgid());
+
+    let path = tempfile().unwrap();
+    let fd = path.as_raw_fd();
+
+    fchown(fd, uid, gid).unwrap();
+    fchown(fd, uid, None).unwrap();
+    fchown(fd, None, gid).unwrap();
+    fchown(999999999, uid, gid).unwrap_err();
+}
+
+#[test]
+#[cfg(not(target_os = "redox"))]
+fn test_fchownat() {
+    let _dr = crate::DirRestore::new();
+    // Testing for anything other than our own UID/GID is hard.
+    let uid = Some(getuid());
+    let gid = Some(getgid());
+
+    let tempdir = tempdir().unwrap();
+    let path = tempdir.path().join("file");
+    {
+        File::create(&path).unwrap();
+    }
+
+    let dirfd = open(tempdir.path(), OFlag::empty(), Mode::empty()).unwrap();
+
+    fchownat(Some(dirfd), "file", uid, gid, FchownatFlags::FollowSymlink)
+        .unwrap();
+
+    chdir(tempdir.path()).unwrap();
+    fchownat(None, "file", uid, gid, FchownatFlags::FollowSymlink).unwrap();
+
+    fs::remove_file(&path).unwrap();
+    fchownat(None, "file", uid, gid, FchownatFlags::FollowSymlink).unwrap_err();
+}
+
+#[test]
+fn test_lseek() {
+    const CONTENTS: &[u8] = b"abcdef123456";
+    let mut tmp = tempfile().unwrap();
+    tmp.write_all(CONTENTS).unwrap();
+    let tmpfd = tmp.into_raw_fd();
+
+    let offset: off_t = 5;
+    lseek(tmpfd, offset, Whence::SeekSet).unwrap();
+
+    let mut buf = [0u8; 7];
+    crate::read_exact(tmpfd, &mut buf);
+    assert_eq!(b"f123456", &buf);
+
+    close(tmpfd).unwrap();
+}
+
+#[cfg(any(target_os = "linux", target_os = "android"))]
+#[test]
+fn test_lseek64() {
+    const CONTENTS: &[u8] = b"abcdef123456";
+    let mut tmp = tempfile().unwrap();
+    tmp.write_all(CONTENTS).unwrap();
+    let tmpfd = tmp.into_raw_fd();
+
+    lseek64(tmpfd, 5, Whence::SeekSet).unwrap();
+
+    let mut buf = [0u8; 7];
+    crate::read_exact(tmpfd, &mut buf);
+    assert_eq!(b"f123456", &buf);
+
+    close(tmpfd).unwrap();
+}
+
+cfg_if! {
+    if #[cfg(any(target_os = "android", target_os = "linux"))] {
+        macro_rules! require_acct{
+            () => {
+                require_capability!("test_acct", CAP_SYS_PACCT);
+            }
+        }
+    } else if #[cfg(target_os = "freebsd")] {
+        macro_rules! require_acct{
+            () => {
+                skip_if_not_root!("test_acct");
+                skip_if_jailed!("test_acct");
+            }
+        }
+    } else if #[cfg(not(any(target_os = "redox", target_os = "fuchsia", target_os = "haiku")))] {
+        macro_rules! require_acct{
+            () => {
+                skip_if_not_root!("test_acct");
+            }
+        }
+    }
+}
+
+#[test]
+#[cfg(not(any(
+    target_os = "redox",
+    target_os = "fuchsia",
+    target_os = "haiku"
+)))]
+fn test_acct() {
+    use std::process::Command;
+    use std::{thread, time};
+    use tempfile::NamedTempFile;
+
+    let _m = crate::FORK_MTX.lock();
+    require_acct!();
+
+    let file = NamedTempFile::new().unwrap();
+    let path = file.path().to_str().unwrap();
+
+    acct::enable(path).unwrap();
+
+    loop {
+        Command::new("echo").arg("Hello world").output().unwrap();
+        let len = fs::metadata(path).unwrap().len();
+        if len > 0 {
+            break;
+        }
+        thread::sleep(time::Duration::from_millis(10));
+    }
+    acct::disable().unwrap();
+}
+
+#[test]
+fn test_fpathconf_limited() {
+    let f = tempfile().unwrap();
+    // AFAIK, PATH_MAX is limited on all platforms, so it makes a good test
+    let path_max = fpathconf(f.as_raw_fd(), PathconfVar::PATH_MAX);
+    assert!(
+        path_max
+            .expect("fpathconf failed")
+            .expect("PATH_MAX is unlimited")
+            > 0
+    );
+}
+
+#[test]
+fn test_pathconf_limited() {
+    // AFAIK, PATH_MAX is limited on all platforms, so it makes a good test
+    let path_max = pathconf("/", PathconfVar::PATH_MAX);
+    assert!(
+        path_max
+            .expect("pathconf failed")
+            .expect("PATH_MAX is unlimited")
+            > 0
+    );
+}
+
+#[test]
+fn test_sysconf_limited() {
+    // AFAIK, OPEN_MAX is limited on all platforms, so it makes a good test
+    let open_max = sysconf(SysconfVar::OPEN_MAX);
+    assert!(
+        open_max
+            .expect("sysconf failed")
+            .expect("OPEN_MAX is unlimited")
+            > 0
+    );
+}
+
+#[cfg(target_os = "freebsd")]
+#[test]
+fn test_sysconf_unsupported() {
+    // I know of no sysconf variables that are unsupported everywhere, but
+    // _XOPEN_CRYPT is unsupported on FreeBSD 11.0, which is one of the platforms
+    // we test.
+    let open_max = sysconf(SysconfVar::_XOPEN_CRYPT);
+    assert!(open_max.expect("sysconf failed").is_none())
+}
+
+#[cfg(any(
+    target_os = "android",
+    target_os = "dragonfly",
+    target_os = "freebsd",
+    target_os = "linux",
+    target_os = "openbsd"
+))]
+#[test]
+fn test_getresuid() {
+    let resuids = getresuid().unwrap();
+    assert_ne!(resuids.real.as_raw(), libc::uid_t::MAX);
+    assert_ne!(resuids.effective.as_raw(), libc::uid_t::MAX);
+    assert_ne!(resuids.saved.as_raw(), libc::uid_t::MAX);
+}
+
+#[cfg(any(
+    target_os = "android",
+    target_os = "dragonfly",
+    target_os = "freebsd",
+    target_os = "linux",
+    target_os = "openbsd"
+))]
+#[test]
+fn test_getresgid() {
+    let resgids = getresgid().unwrap();
+    assert_ne!(resgids.real.as_raw(), libc::gid_t::MAX);
+    assert_ne!(resgids.effective.as_raw(), libc::gid_t::MAX);
+    assert_ne!(resgids.saved.as_raw(), libc::gid_t::MAX);
+}
+
+// Test that we can create a pair of pipes.  No need to verify that they pass
+// data; that's the domain of the OS, not nix.
+#[test]
+fn test_pipe() {
+    let (fd0, fd1) = pipe().unwrap();
+    let m0 = stat::SFlag::from_bits_truncate(
+        stat::fstat(fd0).unwrap().st_mode as mode_t,
+    );
+    // S_IFIFO means it's a pipe
+    assert_eq!(m0, SFlag::S_IFIFO);
+    let m1 = stat::SFlag::from_bits_truncate(
+        stat::fstat(fd1).unwrap().st_mode as mode_t,
+    );
+    assert_eq!(m1, SFlag::S_IFIFO);
+}
+
+// pipe2(2) is the same as pipe(2), except it allows setting some flags.  Check
+// that we can set a flag.
+#[cfg(any(
+    target_os = "android",
+    target_os = "dragonfly",
+    target_os = "emscripten",
+    target_os = "freebsd",
+    target_os = "illumos",
+    target_os = "linux",
+    target_os = "netbsd",
+    target_os = "openbsd",
+    target_os = "redox",
+    target_os = "solaris"
+))]
+#[test]
+fn test_pipe2() {
+    use nix::fcntl::{fcntl, FcntlArg, FdFlag};
+
+    let (fd0, fd1) = pipe2(OFlag::O_CLOEXEC).unwrap();
+    let f0 = FdFlag::from_bits_truncate(fcntl(fd0, FcntlArg::F_GETFD).unwrap());
+    assert!(f0.contains(FdFlag::FD_CLOEXEC));
+    let f1 = FdFlag::from_bits_truncate(fcntl(fd1, FcntlArg::F_GETFD).unwrap());
+    assert!(f1.contains(FdFlag::FD_CLOEXEC));
+}
+
+#[test]
+#[cfg(not(any(target_os = "redox", target_os = "fuchsia")))]
+fn test_truncate() {
+    let tempdir = tempdir().unwrap();
+    let path = tempdir.path().join("file");
+
+    {
+        let mut tmp = File::create(&path).unwrap();
+        const CONTENTS: &[u8] = b"12345678";
+        tmp.write_all(CONTENTS).unwrap();
+    }
+
+    truncate(&path, 4).unwrap();
+
+    let metadata = fs::metadata(&path).unwrap();
+    assert_eq!(4, metadata.len());
+}
+
+#[test]
+fn test_ftruncate() {
+    let tempdir = tempdir().unwrap();
+    let path = tempdir.path().join("file");
+
+    let tmpfd = {
+        let mut tmp = File::create(&path).unwrap();
+        const CONTENTS: &[u8] = b"12345678";
+        tmp.write_all(CONTENTS).unwrap();
+        tmp.into_raw_fd()
+    };
+
+    ftruncate(tmpfd, 2).unwrap();
+    close(tmpfd).unwrap();
+
+    let metadata = fs::metadata(&path).unwrap();
+    assert_eq!(2, metadata.len());
+}
+
+// Used in `test_alarm`.
+#[cfg(not(target_os = "redox"))]
+static mut ALARM_CALLED: bool = false;
+
+// Used in `test_alarm`.
+#[cfg(not(target_os = "redox"))]
+pub extern "C" fn alarm_signal_handler(raw_signal: libc::c_int) {
+    assert_eq!(
+        raw_signal,
+        libc::SIGALRM,
+        "unexpected signal: {}",
+        raw_signal
+    );
+    unsafe { ALARM_CALLED = true };
+}
+
+#[test]
+#[cfg(not(target_os = "redox"))]
+fn test_alarm() {
+    use std::{
+        thread,
+        time::{Duration, Instant},
+    };
+
+    // Maybe other tests that fork interfere with this one?
+    let _m = crate::SIGNAL_MTX.lock();
+
+    let handler = SigHandler::Handler(alarm_signal_handler);
+    let signal_action =
+        SigAction::new(handler, SaFlags::SA_RESTART, SigSet::empty());
+    let old_handler = unsafe {
+        sigaction(Signal::SIGALRM, &signal_action)
+            .expect("unable to set signal handler for alarm")
+    };
+
+    // Set an alarm.
+    assert_eq!(alarm::set(60), None);
+
+    // Overwriting an alarm should return the old alarm.
+    assert_eq!(alarm::set(1), Some(60));
+
+    // We should be woken up after 1 second by the alarm, so we'll sleep for 3
+    // seconds to be sure.
+    let starttime = Instant::now();
+    loop {
+        thread::sleep(Duration::from_millis(100));
+        if unsafe { ALARM_CALLED } {
+            break;
+        }
+        if starttime.elapsed() > Duration::from_secs(3) {
+            panic!("Timeout waiting for SIGALRM");
+        }
+    }
+
+    // Reset the signal.
+    unsafe {
+        sigaction(Signal::SIGALRM, &old_handler)
+            .expect("unable to set signal handler for alarm");
+    }
+}
+
+#[test]
+#[cfg(not(target_os = "redox"))]
+fn test_canceling_alarm() {
+    let _m = crate::SIGNAL_MTX.lock();
+
+    assert_eq!(alarm::cancel(), None);
+
+    assert_eq!(alarm::set(60), None);
+    assert_eq!(alarm::cancel(), Some(60));
+}
+
+#[test]
+#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
+fn test_symlinkat() {
+    let _m = crate::CWD_LOCK.read();
+
+    let tempdir = tempdir().unwrap();
+
+    let target = tempdir.path().join("a");
+    let linkpath = tempdir.path().join("b");
+    symlinkat(&target, None, &linkpath).unwrap();
+    assert_eq!(
+        readlink(&linkpath).unwrap().to_str().unwrap(),
+        target.to_str().unwrap()
+    );
+
+    let dirfd = open(tempdir.path(), OFlag::empty(), Mode::empty()).unwrap();
+    let target = "c";
+    let linkpath = "d";
+    symlinkat(target, Some(dirfd), linkpath).unwrap();
+    assert_eq!(
+        readlink(&tempdir.path().join(linkpath))
+            .unwrap()
+            .to_str()
+            .unwrap(),
+        target
+    );
+}
+
+#[test]
+#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
+fn test_linkat_file() {
+    let tempdir = tempdir().unwrap();
+    let oldfilename = "foo.txt";
+    let oldfilepath = tempdir.path().join(oldfilename);
+
+    let newfilename = "bar.txt";
+    let newfilepath = tempdir.path().join(newfilename);
+
+    // Create file
+    File::create(oldfilepath).unwrap();
+
+    // Get file descriptor for base directory
+    let dirfd =
+        fcntl::open(tempdir.path(), fcntl::OFlag::empty(), stat::Mode::empty())
+            .unwrap();
+
+    // Attempt hard link file at relative path
+    linkat(
+        Some(dirfd),
+        oldfilename,
+        Some(dirfd),
+        newfilename,
+        LinkatFlags::SymlinkFollow,
+    )
+    .unwrap();
+    assert!(newfilepath.exists());
+}
+
+#[test]
+#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
+fn test_linkat_olddirfd_none() {
+    let _dr = crate::DirRestore::new();
+
+    let tempdir_oldfile = tempdir().unwrap();
+    let oldfilename = "foo.txt";
+    let oldfilepath = tempdir_oldfile.path().join(oldfilename);
+
+    let tempdir_newfile = tempdir().unwrap();
+    let newfilename = "bar.txt";
+    let newfilepath = tempdir_newfile.path().join(newfilename);
+
+    // Create file
+    File::create(oldfilepath).unwrap();
+
+    // Get file descriptor for base directory of new file
+    let dirfd = fcntl::open(
+        tempdir_newfile.path(),
+        fcntl::OFlag::empty(),
+        stat::Mode::empty(),
+    )
+    .unwrap();
+
+    // Attempt hard link file using curent working directory as relative path for old file path
+    chdir(tempdir_oldfile.path()).unwrap();
+    linkat(
+        None,
+        oldfilename,
+        Some(dirfd),
+        newfilename,
+        LinkatFlags::SymlinkFollow,
+    )
+    .unwrap();
+    assert!(newfilepath.exists());
+}
+
+#[test]
+#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
+fn test_linkat_newdirfd_none() {
+    let _dr = crate::DirRestore::new();
+
+    let tempdir_oldfile = tempdir().unwrap();
+    let oldfilename = "foo.txt";
+    let oldfilepath = tempdir_oldfile.path().join(oldfilename);
+
+    let tempdir_newfile = tempdir().unwrap();
+    let newfilename = "bar.txt";
+    let newfilepath = tempdir_newfile.path().join(newfilename);
+
+    // Create file
+    File::create(oldfilepath).unwrap();
+
+    // Get file descriptor for base directory of old file
+    let dirfd = fcntl::open(
+        tempdir_oldfile.path(),
+        fcntl::OFlag::empty(),
+        stat::Mode::empty(),
+    )
+    .unwrap();
+
+    // Attempt hard link file using current working directory as relative path for new file path
+    chdir(tempdir_newfile.path()).unwrap();
+    linkat(
+        Some(dirfd),
+        oldfilename,
+        None,
+        newfilename,
+        LinkatFlags::SymlinkFollow,
+    )
+    .unwrap();
+    assert!(newfilepath.exists());
+}
+
+#[test]
+#[cfg(not(any(
+    target_os = "ios",
+    target_os = "macos",
+    target_os = "redox",
+    target_os = "haiku"
+)))]
+fn test_linkat_no_follow_symlink() {
+    let _m = crate::CWD_LOCK.read();
+
+    let tempdir = tempdir().unwrap();
+    let oldfilename = "foo.txt";
+    let oldfilepath = tempdir.path().join(oldfilename);
+
+    let symoldfilename = "symfoo.txt";
+    let symoldfilepath = tempdir.path().join(symoldfilename);
+
+    let newfilename = "nofollowsymbar.txt";
+    let newfilepath = tempdir.path().join(newfilename);
+
+    // Create file
+    File::create(&oldfilepath).unwrap();
+
+    // Create symlink to file
+    symlinkat(&oldfilepath, None, &symoldfilepath).unwrap();
+
+    // Get file descriptor for base directory
+    let dirfd =
+        fcntl::open(tempdir.path(), fcntl::OFlag::empty(), stat::Mode::empty())
+            .unwrap();
+
+    // Attempt link symlink of file at relative path
+    linkat(
+        Some(dirfd),
+        symoldfilename,
+        Some(dirfd),
+        newfilename,
+        LinkatFlags::NoSymlinkFollow,
+    )
+    .unwrap();
+
+    // Assert newfile is actually a symlink to oldfile.
+    assert_eq!(
+        readlink(&newfilepath).unwrap().to_str().unwrap(),
+        oldfilepath.to_str().unwrap()
+    );
+}
+
+#[test]
+#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
+fn test_linkat_follow_symlink() {
+    let _m = crate::CWD_LOCK.read();
+
+    let tempdir = tempdir().unwrap();
+    let oldfilename = "foo.txt";
+    let oldfilepath = tempdir.path().join(oldfilename);
+
+    let symoldfilename = "symfoo.txt";
+    let symoldfilepath = tempdir.path().join(symoldfilename);
+
+    let newfilename = "nofollowsymbar.txt";
+    let newfilepath = tempdir.path().join(newfilename);
+
+    // Create file
+    File::create(&oldfilepath).unwrap();
+
+    // Create symlink to file
+    symlinkat(&oldfilepath, None, &symoldfilepath).unwrap();
+
+    // Get file descriptor for base directory
+    let dirfd =
+        fcntl::open(tempdir.path(), fcntl::OFlag::empty(), stat::Mode::empty())
+            .unwrap();
+
+    // Attempt link target of symlink of file at relative path
+    linkat(
+        Some(dirfd),
+        symoldfilename,
+        Some(dirfd),
+        newfilename,
+        LinkatFlags::SymlinkFollow,
+    )
+    .unwrap();
+
+    let newfilestat = stat::stat(&newfilepath).unwrap();
+
+    // Check the file type of the new link
+    assert_eq!(
+        (stat::SFlag::from_bits_truncate(newfilestat.st_mode as mode_t)
+            & SFlag::S_IFMT),
+        SFlag::S_IFREG
+    );
+
+    // Check the number of hard links to the original file
+    assert_eq!(newfilestat.st_nlink, 2);
+}
+
+#[test]
+#[cfg(not(target_os = "redox"))]
+fn test_unlinkat_dir_noremovedir() {
+    let tempdir = tempdir().unwrap();
+    let dirname = "foo_dir";
+    let dirpath = tempdir.path().join(dirname);
+
+    // Create dir
+    DirBuilder::new().recursive(true).create(dirpath).unwrap();
+
+    // Get file descriptor for base directory
+    let dirfd =
+        fcntl::open(tempdir.path(), fcntl::OFlag::empty(), stat::Mode::empty())
+            .unwrap();
+
+    // Attempt unlink dir at relative path without proper flag
+    let err_result =
+        unlinkat(Some(dirfd), dirname, UnlinkatFlags::NoRemoveDir).unwrap_err();
+    assert!(err_result == Errno::EISDIR || err_result == Errno::EPERM);
+}
+
+#[test]
+#[cfg(not(target_os = "redox"))]
+fn test_unlinkat_dir_removedir() {
+    let tempdir = tempdir().unwrap();
+    let dirname = "foo_dir";
+    let dirpath = tempdir.path().join(dirname);
+
+    // Create dir
+    DirBuilder::new().recursive(true).create(&dirpath).unwrap();
+
+    // Get file descriptor for base directory
+    let dirfd =
+        fcntl::open(tempdir.path(), fcntl::OFlag::empty(), stat::Mode::empty())
+            .unwrap();
+
+    // Attempt unlink dir at relative path with proper flag
+    unlinkat(Some(dirfd), dirname, UnlinkatFlags::RemoveDir).unwrap();
+    assert!(!dirpath.exists());
+}
+
+#[test]
+#[cfg(not(target_os = "redox"))]
+fn test_unlinkat_file() {
+    let tempdir = tempdir().unwrap();
+    let filename = "foo.txt";
+    let filepath = tempdir.path().join(filename);
+
+    // Create file
+    File::create(&filepath).unwrap();
+
+    // Get file descriptor for base directory
+    let dirfd =
+        fcntl::open(tempdir.path(), fcntl::OFlag::empty(), stat::Mode::empty())
+            .unwrap();
+
+    // Attempt unlink file at relative path
+    unlinkat(Some(dirfd), filename, UnlinkatFlags::NoRemoveDir).unwrap();
+    assert!(!filepath.exists());
+}
+
+#[test]
+fn test_access_not_existing() {
+    let tempdir = tempdir().unwrap();
+    let dir = tempdir.path().join("does_not_exist.txt");
+    assert_eq!(
+        access(&dir, AccessFlags::F_OK).err().unwrap(),
+        Errno::ENOENT
+    );
+}
+
+#[test]
+fn test_access_file_exists() {
+    let tempdir = tempdir().unwrap();
+    let path = tempdir.path().join("does_exist.txt");
+    let _file = File::create(path.clone()).unwrap();
+    access(&path, AccessFlags::R_OK | AccessFlags::W_OK)
+        .expect("assertion failed");
+}
+
+//Clippy false positive https://github.com/rust-lang/rust-clippy/issues/9111
+#[allow(clippy::needless_borrow)]
+#[cfg(not(target_os = "redox"))]
+#[test]
+fn test_user_into_passwd() {
+    // get the UID of the "nobody" user
+    #[cfg(not(target_os = "haiku"))]
+    let test_username = "nobody";
+    // "nobody" unavailable on haiku
+    #[cfg(target_os = "haiku")]
+    let test_username = "user";
+
+    let nobody = User::from_name(test_username).unwrap().unwrap();
+    let pwd: libc::passwd = nobody.into();
+    let _: User = (&pwd).into();
+}
+
+/// Tests setting the filesystem UID with `setfsuid`.
+#[cfg(any(target_os = "linux", target_os = "android"))]
+#[test]
+fn test_setfsuid() {
+    use std::os::unix::fs::PermissionsExt;
+    use std::{fs, io, thread};
+    require_capability!("test_setfsuid", CAP_SETUID);
+
+    // get the UID of the "nobody" user
+    let nobody = User::from_name("nobody").unwrap().unwrap();
+
+    // create a temporary file with permissions '-rw-r-----'
+    let file = tempfile::NamedTempFile::new_in("/var/tmp").unwrap();
+    let temp_path = file.into_temp_path();
+    let temp_path_2 = temp_path.to_path_buf();
+    let mut permissions = fs::metadata(&temp_path).unwrap().permissions();
+    permissions.set_mode(0o640);
+
+    // spawn a new thread where to test setfsuid
+    thread::spawn(move || {
+        // set filesystem UID
+        let fuid = setfsuid(nobody.uid);
+        // trying to open the temporary file should fail with EACCES
+        let res = fs::File::open(&temp_path);
+        let err = res.expect_err("assertion failed");
+        assert_eq!(err.kind(), io::ErrorKind::PermissionDenied);
+
+        // assert fuid actually changes
+        let prev_fuid = setfsuid(Uid::from_raw(-1i32 as u32));
+        assert_ne!(prev_fuid, fuid);
+    })
+    .join()
+    .unwrap();
+
+    // open the temporary file with the current thread filesystem UID
+    fs::File::open(temp_path_2).unwrap();
+}
+
+#[test]
+#[cfg(not(any(
+    target_os = "redox",
+    target_os = "fuchsia",
+    target_os = "haiku"
+)))]
+fn test_ttyname() {
+    let fd = posix_openpt(OFlag::O_RDWR).expect("posix_openpt failed");
+    assert!(fd.as_raw_fd() > 0);
+
+    // on linux, we can just call ttyname on the pty master directly, but
+    // apparently osx requires that ttyname is called on a slave pty (can't
+    // find this documented anywhere, but it seems to empirically be the case)
+    grantpt(&fd).expect("grantpt failed");
+    unlockpt(&fd).expect("unlockpt failed");
+    let sname = unsafe { ptsname(&fd) }.expect("ptsname failed");
+    let fds = open(Path::new(&sname), OFlag::O_RDWR, stat::Mode::empty())
+        .expect("open failed");
+    assert!(fds > 0);
+
+    let name = ttyname(fds).expect("ttyname failed");
+    assert!(name.starts_with("/dev"));
+}
+
+#[test]
+#[cfg(not(any(target_os = "redox", target_os = "fuchsia")))]
+fn test_ttyname_not_pty() {
+    let fd = File::open("/dev/zero").unwrap();
+    assert!(fd.as_raw_fd() > 0);
+    assert_eq!(ttyname(fd.as_raw_fd()), Err(Errno::ENOTTY));
+}
+
+#[test]
+#[cfg(not(any(
+    target_os = "redox",
+    target_os = "fuchsia",
+    target_os = "haiku"
+)))]
+fn test_ttyname_invalid_fd() {
+    assert_eq!(ttyname(-1), Err(Errno::EBADF));
+}
+
+#[test]
+#[cfg(any(
+    target_os = "macos",
+    target_os = "ios",
+    target_os = "freebsd",
+    target_os = "openbsd",
+    target_os = "netbsd",
+    target_os = "dragonfly",
+))]
+fn test_getpeereid() {
+    use std::os::unix::net::UnixStream;
+    let (sock_a, sock_b) = UnixStream::pair().unwrap();
+
+    let (uid_a, gid_a) = getpeereid(sock_a.as_raw_fd()).unwrap();
+    let (uid_b, gid_b) = getpeereid(sock_b.as_raw_fd()).unwrap();
+
+    let uid = geteuid();
+    let gid = getegid();
+
+    assert_eq!(uid, uid_a);
+    assert_eq!(gid, gid_a);
+    assert_eq!(uid_a, uid_b);
+    assert_eq!(gid_a, gid_b);
+}
+
+#[test]
+#[cfg(any(
+    target_os = "macos",
+    target_os = "ios",
+    target_os = "freebsd",
+    target_os = "openbsd",
+    target_os = "netbsd",
+    target_os = "dragonfly",
+))]
+fn test_getpeereid_invalid_fd() {
+    // getpeereid is not POSIX, so error codes are inconsistent between different Unices.
+    getpeereid(-1).expect_err("assertion failed");
+}
+
+#[test]
+#[cfg(not(target_os = "redox"))]
+fn test_faccessat_none_not_existing() {
+    use nix::fcntl::AtFlags;
+    let tempdir = tempfile::tempdir().unwrap();
+    let dir = tempdir.path().join("does_not_exist.txt");
+    assert_eq!(
+        faccessat(None, &dir, AccessFlags::F_OK, AtFlags::empty())
+            .err()
+            .unwrap(),
+        Errno::ENOENT
+    );
+}
+
+#[test]
+#[cfg(not(target_os = "redox"))]
+fn test_faccessat_not_existing() {
+    use nix::fcntl::AtFlags;
+    let tempdir = tempfile::tempdir().unwrap();
+    let dirfd = open(tempdir.path(), OFlag::empty(), Mode::empty()).unwrap();
+    let not_exist_file = "does_not_exist.txt";
+    assert_eq!(
+        faccessat(
+            Some(dirfd),
+            not_exist_file,
+            AccessFlags::F_OK,
+            AtFlags::empty(),
+        )
+        .err()
+        .unwrap(),
+        Errno::ENOENT
+    );
+}
+
+#[test]
+#[cfg(not(target_os = "redox"))]
+fn test_faccessat_none_file_exists() {
+    use nix::fcntl::AtFlags;
+    let tempdir = tempfile::tempdir().unwrap();
+    let path = tempdir.path().join("does_exist.txt");
+    let _file = File::create(path.clone()).unwrap();
+    assert!(faccessat(
+        None,
+        &path,
+        AccessFlags::R_OK | AccessFlags::W_OK,
+        AtFlags::empty(),
+    )
+    .is_ok());
+}
+
+#[test]
+#[cfg(not(target_os = "redox"))]
+fn test_faccessat_file_exists() {
+    use nix::fcntl::AtFlags;
+    let tempdir = tempfile::tempdir().unwrap();
+    let dirfd = open(tempdir.path(), OFlag::empty(), Mode::empty()).unwrap();
+    let exist_file = "does_exist.txt";
+    let path = tempdir.path().join(exist_file);
+    let _file = File::create(path.clone()).unwrap();
+    assert!(faccessat(
+        Some(dirfd),
+        &path,
+        AccessFlags::R_OK | AccessFlags::W_OK,
+        AtFlags::empty(),
+    )
+    .is_ok());
+}
+
+#[test]
+#[cfg(any(
+    all(target_os = "linux", not(target_env = "uclibc")),
+    target_os = "freebsd",
+    target_os = "dragonfly"
+))]
+fn test_eaccess_not_existing() {
+    let tempdir = tempdir().unwrap();
+    let dir = tempdir.path().join("does_not_exist.txt");
+    assert_eq!(
+        eaccess(&dir, AccessFlags::F_OK).err().unwrap(),
+        Errno::ENOENT
+    );
+}
+
+#[test]
+#[cfg(any(
+    all(target_os = "linux", not(target_env = "uclibc")),
+    target_os = "freebsd",
+    target_os = "dragonfly"
+))]
+fn test_eaccess_file_exists() {
+    let tempdir = tempdir().unwrap();
+    let path = tempdir.path().join("does_exist.txt");
+    let _file = File::create(path.clone()).unwrap();
+    eaccess(&path, AccessFlags::R_OK | AccessFlags::W_OK)
+        .expect("assertion failed");
+}