rustHow to append to file in Rust

Appending to a file in Rust is a relatively straightforward process. To do so, you need to open the file in write-only mode, seek to the end of the file, and then write the data you want to append. To open the file in write-only mode, you can use the OpenOptions::append method. To seek to the end of the file, you can use the seek method. Finally, to write the data, you can use the write method.

use std::fs::OpenOptions;
use std::io::{Seek, SeekFrom, Write};

fn main() {
    let mut file = OpenOptions::new()
        .write(true)
        .append(true)
        .open("my_file.txt")
        .unwrap();

    file.seek(SeekFrom::End(0)).unwrap();
    file.write(b"This is the data I want to append.").unwrap();
}

The above ## Code example opens the file my_file.txt in write-only mode and appends the data This is the data I want to append. to the end of the file.

Helpful links

• std::fs::OpenOptions
• std::io::Seek
• std::io::Write

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