Exploring Rust's Immutable Path Struct

Introduction

In this lab, we will explore the Path struct in Rust, which represents file paths in the underlying filesystem. It comes in two flavors: posix::Path for UNIX-like systems and windows::Path for Windows. The Path can be created from an OsStr and provides various methods to retrieve information from the file or directory that the path points to. It is important to note that a Path is immutable, and its owned version is called PathBuf, which can be mutated in-place. The relation between Path and PathBuf is similar to that between str and String.

Note: If the lab does not specify a file name, you can use any file name you want. For example, you can use main.rs, compile and run it with rustc main.rs && ./main.

Skills Graph

Path

The Path struct represents file paths in the underlying filesystem. There are two flavors of Path: posix::Path, for UNIX-like systems, and windows::Path, for Windows. The prelude exports the appropriate platform-specific Path variant.

A Path can be created from an OsStr, and provides several methods to get information from the file/directory the path points to.

A Path is immutable. The owned version of Path is PathBuf. The relation between Path and PathBuf is similar to that of str and String: a PathBuf can be mutated in-place, and can be dereferenced to a Path.

Note that a Path is not internally represented as an UTF-8 string, but instead is stored as an OsString. Therefore, converting a Path to a &str is not free and may fail (an Option is returned). However, a Path can be freely converted to an OsString or &OsStr using into_os_string and as_os_str, respectively.

use std::path::Path;

fn main() {
    // Create a `Path` from an `&'static str`
    let path = Path::new(".");

    // The `display` method returns a `Display`able structure
    let _display = path.display();

    // `join` merges a path with a byte container using the OS specific
    // separator, and returns a `PathBuf`
    let mut new_path = path.join("a").join("b");

    // `push` extends the `PathBuf` with a `&Path`
    new_path.push("c");
    new_path.push("myfile.tar.gz");

    // `set_file_name` updates the file name of the `PathBuf`
    new_path.set_file_name("package.tgz");

    // Convert the `PathBuf` into a string slice
    match new_path.to_str() {
        None => panic!("new path is not a valid UTF-8 sequence"),
        Some(s) => println!("new path is {}", s),
    }
}

Be sure to check at other Path methods (posix::Path or windows::Path) and the Metadata struct.

Summary

Congratulations! You have completed the Path lab. You can practice more labs in LabEx to improve your skills.