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法律研究Rust编程中的文件操作
文件操作通常包括I/O操作。Rust为我们提供了不同的方法来处理所有这些操作。
打开
Rust提供了一个open静态方法，我们可以用它以只读模式打开一个文件。
示例
考虑下面显示的代码
use std::fs::File; use std::io::prelude::*; use std::path::Path; fn main() { // Create a path to the desired file let path = Path::new("out.txt"); let display = path.display(); let mut file = match File::open(&path) { Err(why) => panic!("unable to open {}: {}", display, why), Ok(file) => file, }; let mut s = String::new(); match file.read_to_string(&mut s) { Err(why) => panic!("unable to read {}: {}", display, why), Ok(_) => print!("{} it contains:
{}", display, s), } // `file` goes out of scope, and the "out.txt" file gets closed }
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输出
以上代码的输出是
out.txt contains: Hello World!
创建
create方法以只写模式打开一个文件，如果文件已经存在，则删除旧内容。
示例
static RANDOM_TEXT: &str = "Lorem ipsum dolor sit AMEN, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat."; use std::fs::File; use std::io::prelude::*; use std::path::Path; fn main() { let path = Path::new("random_text.txt"); let display = path.display(); // Open a file in write-only mode, returns `io::Result` let mut file = match File::create(&path) { Err(why) => panic!("couldn't create {}: {}", display, why), Ok(file) => file, }; // Write the `RANDOM_TEXT` string to `file`, returns `io::Result<()>` match file.write_all(RANDOM_TEXT.as_bytes()) { Err(why) => panic!("couldn't write to {}: {}", display, why), Ok(_) => println!("successfully wrote to {}", display), } }
输出
当我们运行以下命令时
cat random_text.txt
我们得到的输出是
Lorem ipsum dolor sit AMEN, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
更新于：2021年4月3日
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