How to read a plain text file in Rust

Erick McCollum | 15 Nov 2021

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The Rust programming language is known for its lower-level implementation, similar to that of the C programming language. However, even with this in mind, it is still fairly simple to read the contents of a plain text file using Rust.

For example, assuming that there is a text file named test.txt in the parent directory of a Rust program, one could read the entire contents of that text file using the following code snippet:


    use std::fs;

    fn main() {
        let file_name = "../test.txt";

        println!("Reading the file: {}", file_name);

        let file_content = fs::read_to_string(file_name)
            .expect("Failed to read the file");

        println!("\nFile contents:\n---------------\n{}\n", file_content);
    }

In my example, the above code produced the following output:


    % cargo run

    Reading the file: ../test.txt

    File contents:
    ---------------
    Hello there from test.txt!!!

When compared to a similar approach using the C programming language, the Rust approach is much simpler.

More information may be found in the Rust programming language documentation: Reading a File.

Additionally, the sample code used in this article may be found on my GitHub profile at the following link: code-samples/Rust/read-file.

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