How do you work with file I/O?

Question

Accepted Answer

**std::fs** and **std::io** for file operations.

**Read entire file:**
```rust
let content = std::fs::read_to_string("file.txt")?;
```

**Write file:**
```rust
std::fs::write("output.txt", "Hello!")?;
```

**Buffered read:**
```rust
use std::io::{BufRead, BufReader};
use std::fs::File;

let file = File::open("file.txt")?;
let reader = BufReader::new(file);
for line in reader.lines() {
    println!("{}", line?);
}
```

**Async file I/O:**
```rust
use tokio::io::{AsyncReadExt, AsyncWriteExt};

let mut file = tokio::fs::File::open("file.txt").await?;
let mut contents = String::new();
file.read_to_string(&mut contents).await?;
```

**Key:** fs for sync, tokio::fs for async.

Rust: How do you work with file I/O?