`Path`

While paths can be represented as strings in Rust, we can use PathBuf and Path for code that is easier to maintain, and more reliable. The Path type is helpful in many programs.

Some methods, like current_dir() return a PathBuf, which is a mutable path. We can handle PathBuf as a Path, and convert back into a PathBuf with the to_path_buf() function.

Example

This program gets the current working directory, which is the active directory in a console window. And then it adds a directory to the PathBuf, and then a file name.

Step 1 With the env method current_dir() we get a PathBuf that contains the current working directory.

Step 2 With push() on a PathBuf, we can add a directory. More than one directory can be added.

Step 3 We can pass a reference to a PathBuf to a function that requires a Path reference.

Step 4 To convert back into a PathBuf, which can be changed, from a Path, we can use the to_path_buf() method.

Step 5 To add a file name, we can use push(). We can place an extension on the end of the path if it is needed.

Step 6 To get a str from the PathBuf (or Path) we can use to_str(). On the str, we can get a String by further calling to_string().

use std::env;
use std::path::*;

fn main() {
    // Step 1: get a PathBuf from the env.
    let mut p = env::current_dir().unwrap();

    // Step 2: add a directory.
    p.push("abc");

    // Step 3: pass to a method as a Path.
    add_file_name(&p);
}

fn add_file_name(p: &Path) {
    // Step 4: convert the Path to a PathBuf so we can modify it.
    let mut f = p.to_path_buf();

    // Step 5: add a file name.
    f.push("xyz.txt");

    // Step 6: get a str, which we can use to open a file.
    let file_name = f.to_str().unwrap();
    println!("{}", file_name);
}
C:\Users\mount\OneDrive\Documents\programs\hello-rust\abc\xyz.txt

Summary

Because Path and PathBuf provide helpful features, like handling delimiters in a cross-platform way, they are preferred when building up paths. They can reduce complexity.