rust递归遍历磁盘目录及文件

 Std库实现

//遍历dir目录，找出修改日期距离当前超过age天的文件名称，存入file_list中
fn visit_dir(dir: &Path, file_list: &mut Vec<String>, age: u64) -> io::Result<()> {if dir.is_dir() {for entry in fs::read_dir(dir)? {let entry = entry?;let path = entry.path();if path.is_dir() {visit_dir(&path, file_list, age)?;} else {let file_matedata = fs::metadata(entry.path()).unwrap();let modify_time = file_matedata.modified()?;if modify_time + Duration::from_secs(age * 24 * 60 * 60) < SystemTime::now(){file_list.push(entry.path().to_str().unwrap().to_string());}}}}Ok(())
}//遍历dir目录，找出空目录（内部无文件，无目录）
fn get_empty_dir(dir: &Path, dir_list: &mut Vec<String>) -> io::Result<()>{if !dir.is_dir() {return Ok(());}let read_dir = fs::read_dir(dir)?;let cnt = read_dir.count();if cnt == 0 {dir_list.push(dir.to_str().unwrap().to_owned());return Ok(());}let read_dir = fs::read_dir(dir)?;for entry in read_dir{let entry = entry?;let path = entry.path();if path.is_dir() {get_empty_dir(path.as_path(), dir_list)?;}}Ok(())
}

上述函数实现比较直接，需要注意fs::read_dir()函数返回值后面的?宏，从read_dir返回值中提取结果。如visit_dir、get_empty_dir函数定义返回值不是io::Result类型，使用?宏，会报错。因为?宏还涉及错误传播，需要io::Result参与。

Tokio实现

Rust的异步递归函数实现比较繁琐，为了简化，导入如下Crate：

async-recursion = "1.0.5"

use async_recursion::async_recursion;
#[async_recursion]
async fn visit_dir_async(dir: &Path, file_list: &mut Vec<String>, age: u64) {if dir.is_dir() {//for entry in tokio::fs::read_dir(dir).flat_map().await? {let mut entries = tokio::fs::read_dir(dir).await.unwrap();while let Some(entry) = entries.next_entry().await.unwrap() {let path = entry.path();if path.is_dir() {visit_dir_async(&path, file_list, age).await;} else {let file_matedata = tokio::fs::metadata(entry.path()).await.unwrap();let modify_time = file_matedata.modified().unwrap();if modify_time + Duration::from_secs(age * 24 * 60 * 60) < SystemTime::now(){file_list.push(entry.path().to_str().unwrap().to_string());}}}}()
}#[async_recursion]
async fn get_empty_dir_async(dir: &Path, dir_list: &mut Vec<String>) {println!("check path:{}", dir.to_str().unwrap());if !dir.is_dir() {return;}let mut read_dir = tokio::fs::read_dir(dir).await.unwrap();if let None = read_dir.next_entry().await.unwrap(){println!("find none path");dir_list.push(dir.to_str().unwrap().to_owned());return;}let mut read_dir = tokio::fs::read_dir(dir).await.unwrap();while let Some(entry) = read_dir.next_entry().await.unwrap(){let path = entry.path();if path.is_dir() {get_empty_dir_async(path.as_path(), dir_list).await;}}
}

调用

use tokio::io::{self, BufReader, AsyncBufReadExt, BufWriter, AsyncWriteExt};
use tokio::fs::{File, try_exists, remove_file, read_to_string, copy, read_dir};
use std::path::{PathBuf};use std::fs::File as fsFile;
use std::fs;
use std::path::Path;
use std::fs::{DirEntry};
use std::time::{Duration, SystemTime};#[tokio::main]
async fn main() -> io::Result<()> {let source_dir = "E:\\xxxxxx\\Log\\";//获取目录中的全部文件let mut file_list: Vec<String> = Vec::new();let path = Path::new(source_dir);visit_dir(path, &mut file_list, 30)?;for file in file_list{println!("{}", file);}let mut empty_file_list: Vec<String> = Vec::new();let path = Path::new(source_dir);get_empty_dir(path, &mut empty_file_list)?;for dir in empty_file_list{println!("{}", dir);}println!("====tokio==================================");let source_dir = "E:\\xxxxxx\\Log\\";//获取目录中的全部文件let mut file_list: Vec<String> = Vec::new();let path = Path::new(source_dir);visit_dir_async(path, &mut file_list, 30).await;for dir in file_list{println!("tokio {}", dir);}println!("====tokio==================================");let mut empty_file_list: Vec<String> = Vec::new();get_empty_dir_async(path, &mut empty_file_list).await;for dir in empty_file_list{println!("tokio {}", dir);}Ok(())
}