关于使用fs.readdir进行异步目录搜索有什么想法吗?我意识到我们可以引入递归,并调用read目录函数来读取下一个目录,但我有点担心它不是异步的…
什么好主意吗?我已经看了node-walk,它很棒,但它不能像readdir那样只给我数组中的文件。虽然
寻找这样的输出…
['file1.txt', 'file2.txt', 'dir/file3.txt']
关于使用fs.readdir进行异步目录搜索有什么想法吗?我意识到我们可以引入递归,并调用read目录函数来读取下一个目录,但我有点担心它不是异步的…
什么好主意吗?我已经看了node-walk,它很棒,但它不能像readdir那样只给我数组中的文件。虽然
寻找这样的输出…
['file1.txt', 'file2.txt', 'dir/file3.txt']
当前回答
使用bluebird promise.coroutine:
let promise = require('bluebird'),
PC = promise.coroutine,
fs = promise.promisifyAll(require('fs'));
let getFiles = PC(function*(dir){
let files = [];
let contents = yield fs.readdirAsync(dir);
for (let i = 0, l = contents.length; i < l; i ++) {
//to remove dot(hidden) files on MAC
if (/^\..*/.test(contents[i])) contents.splice(i, 1);
}
for (let i = 0, l = contents.length; i < l; i ++) {
let content = path.resolve(dir, contents[i]);
let contentStat = yield fs.statAsync(content);
if (contentStat && contentStat.isDirectory()) {
let subFiles = yield getFiles(content);
files = files.concat(subFiles);
} else {
files.push(content);
}
}
return files;
});
//how to use
//easy error handling in one place
getFiles(your_dir).then(console.log).catch(err => console.log(err));
其他回答
There are basically two ways of accomplishing this. In an async environment you'll notice that there are two kinds of loops: serial and parallel. A serial loop waits for one iteration to complete before it moves onto the next iteration - this guarantees that every iteration of the loop completes in order. In a parallel loop, all the iterations are started at the same time, and one may complete before another, however, it is much faster than a serial loop. So in this case, it's probably better to use a parallel loop because it doesn't matter what order the walk completes in, just as long as it completes and returns the results (unless you want them in order).
一个平行循环看起来是这样的:
var fs = require('fs');
var path = require('path');
var walk = function(dir, done) {
var results = [];
fs.readdir(dir, function(err, list) {
if (err) return done(err);
var pending = list.length;
if (!pending) return done(null, results);
list.forEach(function(file) {
file = path.resolve(dir, file);
fs.stat(file, function(err, stat) {
if (stat && stat.isDirectory()) {
walk(file, function(err, res) {
results = results.concat(res);
if (!--pending) done(null, results);
});
} else {
results.push(file);
if (!--pending) done(null, results);
}
});
});
});
};
一个串行循环看起来像这样:
var fs = require('fs');
var path = require('path');
var walk = function(dir, done) {
var results = [];
fs.readdir(dir, function(err, list) {
if (err) return done(err);
var i = 0;
(function next() {
var file = list[i++];
if (!file) return done(null, results);
file = path.resolve(dir, file);
fs.stat(file, function(err, stat) {
if (stat && stat.isDirectory()) {
walk(file, function(err, res) {
results = results.concat(res);
next();
});
} else {
results.push(file);
next();
}
});
})();
});
};
并且在你的主目录中测试它(警告:如果你的主目录中有很多东西,结果列表将会非常大):
walk(process.env.HOME, function(err, results) {
if (err) throw err;
console.log(results);
});
编辑:改进的示例。
我最近编写了这个代码,并认为在这里分享它是有意义的。代码使用了异步库。
var fs = require('fs');
var async = require('async');
var scan = function(dir, suffix, callback) {
fs.readdir(dir, function(err, files) {
var returnFiles = [];
async.each(files, function(file, next) {
var filePath = dir + '/' + file;
fs.stat(filePath, function(err, stat) {
if (err) {
return next(err);
}
if (stat.isDirectory()) {
scan(filePath, suffix, function(err, results) {
if (err) {
return next(err);
}
returnFiles = returnFiles.concat(results);
next();
})
}
else if (stat.isFile()) {
if (file.indexOf(suffix, file.length - suffix.length) !== -1) {
returnFiles.push(filePath);
}
next();
}
});
}, function(err) {
callback(err, returnFiles);
});
});
};
你可以这样使用它:
scan('/some/dir', '.ext', function(err, files) {
// Do something with files that ends in '.ext'.
console.log(files);
});
我修改了老特雷弗的承诺为蓝鸟工作的基础上的答案
var fs = require('fs'),
path = require('path'),
Promise = require('bluebird');
var readdirAsync = Promise.promisify(fs.readdir);
var statAsync = Promise.promisify(fs.stat);
function walkFiles (directory) {
var results = [];
return readdirAsync(directory).map(function(file) {
file = path.join(directory, file);
return statAsync(file).then(function(stat) {
if (stat.isFile()) {
return results.push(file);
}
return walkFiles(file).then(function(filesInDir) {
results = results.concat(filesInDir);
});
});
}).then(function() {
return results;
});
}
//use
walkDir(__dirname).then(function(files) {
console.log(files);
}).catch(function(e) {
console.error(e); {
});
另一个简单而有用的方法
function walkDir(root) {
const stat = fs.statSync(root);
if (stat.isDirectory()) {
const dirs = fs.readdirSync(root).filter(item => !item.startsWith('.'));
let results = dirs.map(sub => walkDir(`${root}/${sub}`));
return [].concat(...results);
} else {
return root;
}
}
TypeScript中基于承诺的递归解决方案,使用Array.flat()处理嵌套返回。
import { resolve } from 'path'
import { Dirent } from 'fs'
import * as fs from 'fs'
function getFiles(root: string): Promise<string[]> {
return fs.promises
.readdir(root, { withFileTypes: true })
.then(dirents => {
const mapToPath = (r: string) => (dirent: Dirent): string => resolve(r, dirent.name)
const directoryPaths = dirents.filter(a => a.isDirectory()).map(mapToPath(root))
const filePaths = dirents.filter(a => a.isFile()).map(mapToPath(root))
return Promise.all<string>([
...directoryPaths.map(a => getFiles(a, include)).flat(),
...filePaths.map(a => Promise.resolve(a))
]).then(a => a.flat())
})
}