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
为了好玩,这里有一个基于流的版本,它与highland.js streams库一起工作。作者之一是维克多·伍。
###
directory >---m------> dirFilesStream >---------o----> out
| |
| |
+--------< returnPipe <-----------+
legend: (m)erge (o)bserve
+ directory has the initial file
+ dirListStream does a directory listing
+ out prints out the full path of the file
+ returnPipe runs stat and filters on directories
###
_ = require('highland')
fs = require('fs')
fsPath = require('path')
directory = _(['someDirectory'])
mergePoint = _()
dirFilesStream = mergePoint.merge().flatMap((parentPath) ->
_.wrapCallback(fs.readdir)(parentPath).sequence().map (path) ->
fsPath.join parentPath, path
)
out = dirFilesStream
# Create the return pipe
returnPipe = dirFilesStream.observe().flatFilter((path) ->
_.wrapCallback(fs.stat)(path).map (v) ->
v.isDirectory()
)
# Connect up the merge point now that we have all of our streams.
mergePoint.write directory
mergePoint.write returnPipe
mergePoint.end()
# Release backpressure. This will print files as they are discovered
out.each H.log
# Another way would be to queue them all up and then print them all out at once.
# out.toArray((files)-> console.log(files))
其他回答
有一个名为cup-readdir的新模块,可以快速递归地搜索目录。它使用异步承诺,在处理深层目录结构时性能优于许多流行的模块。
它可以返回数组中的所有文件,并根据它们的属性对它们进行排序,但缺乏文件过滤和进入符号链接目录等功能。这对于只想从目录中获取每个文件的大型项目非常有用。这里是他们项目主页的链接。
使用async/await,这应该工作:
const FS = require('fs');
const readDir = promisify(FS.readdir);
const fileStat = promisify(FS.stat);
async function getFiles(dir) {
let files = await readDir(dir);
let result = files.map(file => {
let path = Path.join(dir,file);
return fileStat(path).then(stat => stat.isDirectory() ? getFiles(path) : path);
});
return flatten(await Promise.all(result));
}
function flatten(arr) {
return Array.prototype.concat(...arr);
}
你可以用蓝鸟。许诺或许诺:
/**
* Returns a function that will wrap the given `nodeFunction`. Instead of taking a callback, the returned function will return a promise whose fate is decided by the callback behavior of the given node function. The node function should conform to node.js convention of accepting a callback as last argument and calling that callback with error as the first argument and success value on the second argument.
*
* @param {Function} nodeFunction
* @returns {Function}
*/
module.exports = function promisify(nodeFunction) {
return function(...args) {
return new Promise((resolve, reject) => {
nodeFunction.call(this, ...args, (err, data) => {
if(err) {
reject(err);
} else {
resolve(data);
}
})
});
};
};
Node 8+内置了Promisify
请参阅我对生成器方法的其他回答,它可以更快地得到结果。
独立承诺实现
在这个例子中,我使用的是when.js承诺库。
var fs = require('fs')
, path = require('path')
, when = require('when')
, nodefn = require('when/node/function');
function walk (directory, includeDir) {
var results = [];
return when.map(nodefn.call(fs.readdir, directory), function(file) {
file = path.join(directory, file);
return nodefn.call(fs.stat, file).then(function(stat) {
if (stat.isFile()) { return results.push(file); }
if (includeDir) { results.push(file + path.sep); }
return walk(file, includeDir).then(function(filesInDir) {
results = results.concat(filesInDir);
});
});
}).then(function() {
return results;
});
};
walk(__dirname).then(function(files) {
console.log(files);
}).otherwise(function(error) {
console.error(error.stack || error);
});
我包含了一个可选参数includeDir,如果设置为true,它将在文件列表中包含目录。
另一个很好的npm包是glob。
npm公司
它非常强大,应该能满足你所有的递归需求。
编辑:
实际上我对glob不是很满意,所以我创建了readdirp。
我非常有信心,它的API使得递归地查找文件和目录以及应用特定的过滤器非常容易。
阅读它的文档,以更好地了解它的功能和安装方式:
NPM安装readdirp
另一个答案,但这次使用的是TypeScript:
/** * Recursively walk a directory asynchronously and obtain all file names (with full path). * * @param dir Folder name you want to recursively process * @param done Callback function, returns all files with full path. * @param filter Optional filter to specify which files to include, * e.g. for json files: (f: string) => /.json$/.test(f) */ const walk = ( dir: string, done: (err: Error | null, results ? : string[]) => void, filter ? : (f: string) => boolean ) => { let results: string[] = []; fs.readdir(dir, (err: Error, list: string[]) => { if (err) { return done(err); } let pending = list.length; if (!pending) { return done(null, results); } list.forEach((file: string) => { file = path.resolve(dir, file); fs.stat(file, (err2, stat) => { if (stat && stat.isDirectory()) { walk(file, (err3, res) => { if (res) { results = results.concat(res); } if (!--pending) { done(null, results); } }, filter); } else { if (typeof filter === 'undefined' || (filter && filter(file))) { results.push(file); } if (!--pending) { done(null, results); } } }); }); }); };