Provide remove_dir_contents

This is the caller for remove_file_or_dir_all so we can get rid of the
temporary `#[allow]` annocations.

Signed-off-by: Ian Jackson <[email protected]>

Author: ijackson

README.md

@@ -9,6 +9,9 @@
 A reliable implementation of `remove_dir_all` for Windows. For Unix systems
 re-exports `std::fs::remove_dir_all`.
 
+Also provides `remove_dir_contents` for both Windows and Unix.  This
+removes just the contents of the directory, if it exists.
+
 ```rust,no_run
 extern crate remove_dir_all;
 

src/lib.rs

@@ -2,9 +2,8 @@
 //!
 //! This library provides a reliable implementation of `remove_dir_all` for Windows.
 //! For Unix systems, it re-exports `std::fs::remove_dir_all`.
-
-#![allow(unused_imports)] // temporary
-#![allow(dead_code)] // temporary
+//!
+//! It also provides `remove_dir_contents` for both Unix and Windows.
 
 #![deny(missing_debug_implementations)]
 #![deny(missing_docs)]
@@ -36,3 +35,6 @@ use self::unix::remove_file_or_dir_all;
 
 #[cfg(not(windows))]
 pub use std::fs::remove_dir_all;
+
+mod portable;
+pub use portable::*;

src/portable.rs

@@ -0,0 +1,30 @@
+use std::fs;
+use std::io;
+use std::path::Path;
+
+/// Deletes the contents of `dir_path`, but not the directory iteself.
+///
+/// If `dir_path` is a symlink to a directory, deletes the contents
+/// of that directory.  If `dir_path` does not exist, simply returns
+/// (without deleting anything).
+pub fn remove_dir_contents(dir_path: &Path) -> Result<(), io::Error> {
+    // On Unix, looking into the directory and removing the entries
+    // separately is obviously right.
+    //
+    // On Windows, it is also right.  For non-directories,
+    // `remove_file_or_dir_all` is obviously right.  For directories,
+    // we want to treat our `dir_path` as the base dir for the complex
+    // `remove_some` implementation.
+
+    let entries = match fs::read_dir(dir_path) {
+        Err(e) if e.kind() == io::ErrorKind::NotFound => return Ok(()),
+        r => r,
+    }?;
+
+    for entry in entries {
+        let entry_path = entry?.path();
+        crate::remove_file_or_dir_all(&entry_path)?;
+    }
+
+    Ok(())
+}

src/unix.rs

@@ -6,6 +6,7 @@ extern crate libc;
 
 pub(crate) fn remove_file_or_dir_all<P: AsRef<Path>>(path: P) -> io::Result<()> {
     match fs::remove_file(&path) {
+        // Unfortunately, there is no ErrorKind for EISDIR
         Err(e) if e.raw_os_error() == Some(libc::EISDIR) => fs::remove_dir_all(&path),
         r => r,
     }