add unix implementation for create_dir

Author: Qelxiros

library/std/src/fs.rs

@@ -1613,6 +1613,33 @@ impl Dir {
         self.inner.open_with(path, &opts.0).map(|f| File { inner: f })
     }
 
+    /// Attempts to create a directory relative to this directory.
+    ///
+    /// # Errors
+    ///
+    /// This function will return an error in these (and other) situations:
+    /// * The path exists
+    /// * The process doesn't have permission to create the directory
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// #![feature(dirfd)]
+    /// use std::{fs::{Dir, OpenOptions}, io::Read};
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let dir = Dir::new("foo")?;
+    ///     let mut f = dir.open_with("bar.txt", OpenOptions::new().read(true))?;
+    ///     let mut data = vec![];
+    ///     f.read_to_end(&mut data)?;
+    ///     Ok(())
+    /// }
+    /// ```
+    #[unstable(feature = "dirfd", issue = "120426")]
+    pub fn create_dir<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {
+        self.inner.create_dir(path)
+    }
+
     /// Attempts to remove a file relative to this directory.
     ///
     /// # Errors

library/std/src/sys/fs/unix.rs

@@ -54,8 +54,8 @@ use libc::{c_int, mode_t};
 #[cfg(target_os = "android")]
 use libc::{
     dirent as dirent64, fstat as fstat64, fstatat as fstatat64, ftruncate64, lseek64,
-    lstat as lstat64, off64_t, open as open64, openat as openat64, renameat, stat as stat64,
-    unlinkat,
+    lstat as lstat64, mkdirat, off64_t, open as open64, openat as openat64, renameat,
+    stat as stat64, unlinkat,
 };
 #[cfg(not(any(
     all(target_os = "linux", not(target_env = "musl")),
@@ -65,7 +65,7 @@ use libc::{
 )))]
 use libc::{
     dirent as dirent64, fstat as fstat64, ftruncate as ftruncate64, lseek as lseek64,
-    lstat as lstat64, off_t as off64_t, open as open64, openat as openat64, renameat,
+    lstat as lstat64, mkdirat, off_t as off64_t, open as open64, openat as openat64, renameat,
     stat as stat64, unlinkat,
 };
 #[cfg(any(
@@ -74,8 +74,8 @@ use libc::{
     target_os = "hurd"
 ))]
 use libc::{
-    dirent64, fstat64, ftruncate64, lseek64, lstat64, off64_t, open64, openat64, renameat, stat64,
-    unlinkat,
+    dirent64, fstat64, ftruncate64, lseek64, lstat64, mkdirat, off64_t, open64, openat64, renameat,
+    stat64, unlinkat,
 };
 
 use crate::ffi::{CStr, OsStr, OsString};
@@ -295,6 +295,10 @@ impl Dir {
         run_path_with_cstr(path.as_ref(), &|path| self.open_c(path, opts))
     }
 
+    pub fn create_dir<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {
+        run_path_with_cstr(path.as_ref(), &|path| self.create_dir_c(path))
+    }
+
     pub fn remove_file<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {
         run_path_with_cstr(path.as_ref(), &|path| self.remove_c(path, false))
     }
@@ -335,6 +339,10 @@ impl Dir {
         Ok(Self(unsafe { OwnedFd::from_raw_fd(fd) }))
     }
 
+    pub fn create_dir_c(&self, path: &CStr) -> io::Result<()> {
+        cvt(unsafe { mkdirat(self.0.as_raw_fd(), path.as_ptr(), 0o777) }).map(|_| ())
+    }
+
     pub fn remove_c(&self, path: &CStr, remove_dir: bool) -> io::Result<()> {
         cvt(unsafe {
             unlinkat(

library/std/src/sys/fs/windows.rs

@@ -937,9 +937,9 @@ impl Dir {
     }
 
     pub fn create_dir<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {
-        run_path_with_wcstr(path, &|path| {
-            self.create_dir_native(path, &OpenOptions::new()).map(|_| ())
-        })
+        let mut opts = OpenOptions::new();
+        opts.write(true);
+        run_path_with_wcstr(path, &|path| self.create_dir_native(path, &opts).map(|_| ()))
     }
 
     pub fn remove_file<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {