Crate tempfile

source ·
Expand description

Temporary files and directories.

  • Use the tempfile() function for temporary files
  • Use the tempdir() function for temporary directories.

Design

This crate provides several approaches to creating temporary files and directories. tempfile() relies on the OS to remove the temporary file once the last handle is closed. TempDir and NamedTempFile both rely on Rust destructors for cleanup.

When choosing between the temporary file variants, prefer tempfile unless you either need to know the file’s path or to be able to persist it.

Resource Leaking

tempfile will (almost) never fail to cleanup temporary resources, but TempDir and NamedTempFile will if their destructors don’t run. This is because tempfile relies on the OS to cleanup the underlying file, while TempDir and NamedTempFile rely on their destructors to do so.

Security

In the presence of pathological temporary file cleaner, relying on file paths is unsafe because a temporary file cleaner could delete the temporary file which an attacker could then replace.

tempfile doesn’t rely on file paths so this isn’t an issue. However, NamedTempFile does rely on file paths for some operations. See the security documentation on the NamedTempFile type for more information.

Examples

Create a temporary file and write some data into it:

use tempfile::tempfile;
use std::io::{self, Write};

// Create a file inside of `std::env::temp_dir()`.
let mut file = tempfile()?;

writeln!(file, "Brian was here. Briefly.")?;

Create a named temporary file and open an independent file handle:

use tempfile::NamedTempFile;
use std::io::{self, Write, Read};

let text = "Brian was here. Briefly.";

// Create a file inside of `std::env::temp_dir()`.
let mut file1 = NamedTempFile::new()?;

// Re-open it.
let mut file2 = file1.reopen()?;

// Write some test data to the first handle.
file1.write_all(text.as_bytes())?;

// Read the test data using the second handle.
let mut buf = String::new();
file2.read_to_string(&mut buf)?;
assert_eq!(buf, text);

Create a temporary directory and add a file to it:

use tempfile::tempdir;
use std::fs::File;
use std::io::{self, Write};

// Create a directory inside of `std::env::temp_dir()`.
let dir = tempdir()?;

let file_path = dir.path().join("my-temporary-note.txt");
let mut file = File::create(file_path)?;
writeln!(file, "Brian was here. Briefly.")?;

// By closing the `TempDir` explicitly, we can check that it has
// been deleted successfully. If we don't close it explicitly,
// the directory will still be deleted when `dir` goes out
// of scope, but we won't know whether deleting the directory
// succeeded.
drop(file);
dir.close()?;

Structs

Create a new temporary file or directory with custom parameters.
A named temporary file.
Error returned when persisting a temporary file path fails.
Error returned when persisting a temporary file fails.
An object that behaves like a regular temporary file, but keeps data in memory until it reaches a configured size, at which point the data is written to a temporary file on disk, and further operations use the file on disk.
A directory in the filesystem that is automatically deleted when it goes out of scope.
A path to a named temporary file without an open file handle.

Functions

Create a new spooled temporary file.
Create a new temporary directory.
Create a new temporary directory.
Create a new temporary file.
Create a new temporary file in the specified directory.