// Copyright 2019 Intel Corporation. All Rights Reserved.
//
// Copyright 2017 The Chromium OS Authors. All rights reserved.
//
// SPDX-License-Identifier: BSD-3-Clause
//! Structure for handling temporary directories.
use std::env::temp_dir;
use std::ffi::{CString, OsStr, OsString};
use std::fs;
use std::os::unix::ffi::OsStringExt;
use std::path::{Path, PathBuf};
use crate::errno::{errno_result, Error, Result};
/// Wrapper over a temporary directory.
///
/// The directory will be maintained for the lifetime of the `TempDir` object.
pub struct TempDir {
path: PathBuf,
}
impl TempDir {
/// Creates a new temporary directory with `prefix`.
///
/// The directory will be removed when the object goes out of scope.
///
/// # Examples
///
/// ```
/// # use vmm_sys_util::tempdir::TempDir;
/// let t = TempDir::new_with_prefix("/tmp/testdir").unwrap();
/// ```
pub fn new_with_prefix<P: AsRef<OsStr>>(prefix: P) -> Result<TempDir> {
let mut dir_string = prefix.as_ref().to_os_string();
dir_string.push("XXXXXX");
// unwrap this result as the internal bytes can't have a null with a valid path.
let dir_name = CString::new(dir_string.into_vec()).unwrap();
let mut dir_bytes = dir_name.into_bytes_with_nul();
// SAFETY: Creating the directory isn't unsafe. The fact that it modifies the guts of the
// path is also OK because it only overwrites the last 6 Xs added above.
let ret = unsafe { libc::mkdtemp(dir_bytes.as_mut_ptr() as *mut libc::c_char) };
if ret.is_null() {
return errno_result();
}
dir_bytes.pop(); // Remove the null becasue from_vec can't handle it.
Ok(TempDir {
path: PathBuf::from(OsString::from_vec(dir_bytes)),
})
}
/// Creates a new temporary directory with inside `path`.
///
/// The directory will be removed when the object goes out of scope.
///
/// # Examples
///
/// ```
/// # use std::path::Path;
/// # use vmm_sys_util::tempdir::TempDir;
/// let t = TempDir::new_in(Path::new("/tmp/")).unwrap();
/// ```
pub fn new_in(path: &Path) -> Result<TempDir> {
let mut path_buf = path.canonicalize().unwrap();
// This `push` adds a trailing slash ("/whatever/path" -> "/whatever/path/").
// This is safe for paths with already trailing slash.
path_buf.push("");
let temp_dir = TempDir::new_with_prefix(path_buf)?;
Ok(temp_dir)
}
/// Creates a new temporary directory with inside `$TMPDIR` if set, otherwise in `/tmp`.
///
/// The directory will be removed when the object goes out of scope.
///
/// # Examples
///
/// ```
/// # use vmm_sys_util::tempdir::TempDir;
/// let t = TempDir::new().unwrap();
/// ```
pub fn new() -> Result<TempDir> {
let mut in_tmp_dir = temp_dir();
// This `push` adds a trailing slash ("/tmp" -> "/tmp/").
// This is safe for paths with already trailing slash.
in_tmp_dir.push("");
let temp_dir = TempDir::new_in(in_tmp_dir.as_path())?;
Ok(temp_dir)
}
/// Removes the temporary directory.
///
/// Calling this is optional as when a `TempDir` object goes out of scope,
/// the directory will be removed.
/// Calling remove explicitly allows for better error handling.
///
/// # Errors
///
/// This function can only be called once per object. An error is returned
/// otherwise.
///
/// # Examples
///
/// ```
/// # use std::path::Path;
/// # use std::path::PathBuf;
/// # use vmm_sys_util::tempdir::TempDir;
/// let temp_dir = TempDir::new_with_prefix("/tmp/testdir").unwrap();
/// temp_dir.remove().unwrap();
pub fn remove(&self) -> Result<()> {
fs::remove_dir_all(&self.path).map_err(Error::from)
}
/// Returns the path to the tempdir.
///
/// # Examples
///
/// ```
/// # use std::path::Path;
/// # use std::path::PathBuf;
/// # use vmm_sys_util::tempdir::TempDir;
/// let temp_dir = TempDir::new_with_prefix("/tmp/testdir").unwrap();
/// assert!(temp_dir.as_path().exists());
pub fn as_path(&self) -> &Path {
self.path.as_ref()
}
}
impl Drop for TempDir {
fn drop(&mut self) {
let _ = self.remove();
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_create_dir() {
let t = TempDir::new().unwrap();
let path = t.as_path();
assert!(path.exists());
assert!(path.is_dir());
assert!(path.starts_with(temp_dir()));
}
#[test]
fn test_create_dir_with_prefix() {
let t = TempDir::new_with_prefix("/tmp/testdir").unwrap();
let path = t.as_path();
assert!(path.exists());
assert!(path.is_dir());
assert!(path.to_str().unwrap().contains("/tmp/testdir"));
}
#[test]
fn test_remove_dir() {
use crate::tempfile::TempFile;
let t = TempDir::new().unwrap();
let path = t.as_path().to_owned();
assert!(t.remove().is_ok());
// Calling remove twice returns error.
assert!(t.remove().is_err());
assert!(!path.exists());
let t = TempDir::new().unwrap();
let mut file = TempFile::new_in(t.as_path()).unwrap();
let t2 = TempDir::new_in(t.as_path()).unwrap();
let mut file2 = TempFile::new_in(t2.as_path()).unwrap();
let path2 = t2.as_path().to_owned();
assert!(t.remove().is_ok());
// Calling t2.remove returns error because parent dir has removed
assert!(t2.remove().is_err());
assert!(!path2.exists());
assert!(file.remove().is_err());
assert!(file2.remove().is_err());
}
#[test]
fn test_create_dir_in() {
let t = TempDir::new_in(Path::new("/tmp")).unwrap();
let path = t.as_path();
assert!(path.exists());
assert!(path.is_dir());
assert!(path.starts_with("/tmp/"));
let t = TempDir::new_in(Path::new("/tmp")).unwrap();
let path = t.as_path();
assert!(path.exists());
assert!(path.is_dir());
assert!(path.starts_with("/tmp"));
}
#[test]
fn test_drop() {
use std::mem::drop;
let t = TempDir::new_with_prefix("/tmp/asdf").unwrap();
let path = t.as_path().to_owned();
// Force tempdir object to go out of scope.
drop(t);
assert!(!(path.exists()));
}
}