如果文件不存在，我如何读取文件或将其连同其目录一起创建？

Question

I want to read a file into a vector, but if it doesn't exist, I don't want the program to panic. Instead, I want the file to be created (with empty contents). If the directory doesn't exist, I want it to be created, too.

How can I do this automatically in Rust?

This is my current code:

pub fn read(path: &str) -> Vec<String> {
    let file = File::open(path).unwrap();
    let reader = BufReader::new(file);
    let mut history = Vec::new();
    for line in reader.lines() {
        history.push(line.unwrap());
    }
    history
}

Answer 1

Ingredients:

• Recursively create a directory: create_dir_all
• Create files:File::create or OpenOptions

If you do not want your program to panic, unwrap is not your friend, as it panics as soon as you call it on an Err . Now, given that file operations - generally speaking - could always go wrong, you must decide what to do if a file operation fails. Simply returning an empty Vec without any associated file?

Regarding this, error handling , in particular with Result is a worthwhile read.