如何在node.js上移动文件(如mv命令shell) ?是否有任何方法,或者我应该读取一个文件,写到一个新文件,并删除旧文件?


当前回答

跑龙套。节点0.10弃用Pump,产生警告信息

 util.pump() is deprecated. Use readableStream.pipe() instead

因此,使用流复制文件的解决方案是:

var source = fs.createReadStream('/path/to/source');
var dest = fs.createWriteStream('/path/to/dest');

source.pipe(dest);
source.on('end', function() { /* copied */ });
source.on('error', function(err) { /* error */ });

其他回答

我将把所有涉及的函数(即重命名,复制,断开链接)彼此分离,以获得灵活性,并承诺一切,当然:

const renameFile = (path, newPath) => 
  new Promise((res, rej) => {
    fs.rename(path, newPath, (err, data) =>
      err
        ? rej(err)
        : res(data));
  });

const copyFile = (path, newPath, flags) =>
  new Promise((res, rej) => {
    const readStream = fs.createReadStream(path),
      writeStream = fs.createWriteStream(newPath, {flags});

    readStream.on("error", rej);
    writeStream.on("error", rej);
    writeStream.on("finish", res);
    readStream.pipe(writeStream);
  });

const unlinkFile = path => 
  new Promise((res, rej) => {
    fs.unlink(path, (err, data) =>
      err
        ? rej(err)
        : res(data));
  });

const moveFile = (path, newPath, flags) =>
  renameFile(path, newPath)
    .catch(e => {
      if (e.code !== "EXDEV")
        throw new e;

      else
        return copyFile(path, newPath, flags)
          .then(() => unlinkFile(path));
    });

moveFile只是一个方便的函数,我们可以分别应用这些函数,例如,当我们需要更细粒度的异常处理时。

这是对teoman shipahi的回答的重新讨论,使用了一个稍微不那么模糊的名称,并遵循了在尝试调用代码之前定义代码的设计原则。(虽然node允许您做其他事情,但本末倒置并不是一个好的实践。)

function rename_or_copy_and_delete (oldPath, newPath, callback) {

    function copy_and_delete () {
        var readStream = fs.createReadStream(oldPath);
        var writeStream = fs.createWriteStream(newPath);

        readStream.on('error', callback);
        writeStream.on('error', callback);
        readStream.on('close', 
              function () {
                fs.unlink(oldPath, callback);
              }
        );

        readStream.pipe(writeStream);
    }

    fs.rename(oldPath, newPath, 
        function (err) {
          if (err) {
              if (err.code === 'EXDEV') {
                  copy_and_delete();
              } else {
                  callback(err);
              }
              return;// << both cases (err/copy_and_delete)
          }
          callback();
        }
    );
}

下面是一个使用util的例子。我如何移动文件a到不同的分区或设备在Node.js?

var fs = require('fs'),
    util = require('util');

var is = fs.createReadStream('source_file')
var os = fs.createWriteStream('destination_file');

util.pump(is, os, function() {
    fs.unlinkSync('source_file');
});

本地使用nodejs

var fs = require('fs')

var oldPath = 'old/path/file.txt'
var newPath = 'new/path/file.txt'

fs.rename(oldPath, newPath, function (err) {
  if (err) throw err
  console.log('Successfully renamed - AKA moved!')
})

(注意:“如果您正在跨分区或使用不支持移动文件的虚拟文件系统,这将不起作用。[…——Flavien Volken 15年9月2日12:50)

就像上面的回答中所说的那样,我的2分:copy()方法不应该在没有轻微调整的情况下原样用于复制文件:

function copy(callback) {
    var readStream = fs.createReadStream(oldPath);
    var writeStream = fs.createWriteStream(newPath);

    readStream.on('error', callback);
    writeStream.on('error', callback);

    // Do not callback() upon "close" event on the readStream
    // readStream.on('close', function () {
    // Do instead upon "close" on the writeStream
    writeStream.on('close', function () {
        callback();
    });

    readStream.pipe(writeStream);
}

复制函数封装在Promise中:

function copy(oldPath, newPath) {
  return new Promise((resolve, reject) => {
    const readStream = fs.createReadStream(oldPath);
    const writeStream = fs.createWriteStream(newPath);

    readStream.on('error', err => reject(err));
    writeStream.on('error', err => reject(err));

    writeStream.on('close', function() {
      resolve();
    });

    readStream.pipe(writeStream);
  })

但是,请记住,如果目标文件夹不存在,文件系统可能会崩溃。