nodejs文本文件的读写

文本文件的换行符

方法一：
var EOL = fileContents.indexOf("\r\n") >= 0 ? "\r\n" : "\n";

方法二：
var EOL = (process.platform === \'win32\' ? \'\r\n\' : \'\n\')

删除文件

var fs = require("fs");

console.log("Going to delete an existing file");
fs.unlink(\'input.txt\', function(err) {
   if (err) {
      return console.error(err);
   }
   console.log("File deleted successfully!");
});

小文件的异步与同步读写

var fs = require("fs");

console.log("Going to write into existing file");
fs.writeFile(\'input.txt\', \'Simply Easy Learning!\', function(err) {
   if (err) {
      return console.error(err);
   }
   
   console.log("Data written successfully!");
   console.log("Let\'s read newly written data");
   
   fs.readFile(\'input.txt\', function (err, data) {
      if (err) {
         return console.error(err);
      }
      console.log("Asynchronous read: " + data.toString());
   });
});

同步和异步的对比：
var fs = require("fs");

// Asynchronous read
fs.readFile(\'input.txt\', function (err, data) {
   if (err) {
      return console.error(err);
   }
   console.log("Asynchronous read: " + data.toString());
});

// Synchronous read
var data = fs.readFileSync(\'input.txt\');
console.log("Synchronous read: " + data.toString());

console.log("Program Ended");

读写大文件

var fs = require("fs");
var data = \'\';

// Create a readable stream
var readerStream = fs.createReadStream(\'input.txt\');

// Set the encoding to be utf8. 
readerStream.setEncoding(\'UTF8\');

// Handle stream events --> data, end, and error
readerStream.on(\'data\', function(chunk) {
   data += chunk;
});

readerStream.on(\'end\',function() {
   console.log(data);
});

readerStream.on(\'error\', function(err) {
   console.log(err.stack);
});

console.log("Program Ended");
输出如下：
Program Ended
Tutorials Point is giving self learning content
to teach the world in simple and easy way!!!!!

使用async/await

const fs = require(\'fs\').promises;

try {
  const data = await fs.readFile(\'file1.js\'); // need to be in an async function
  console.log(data); // the contents of file1.js
} catch (error) {
  console.log(error)
}

const data = "Hello my name is Hugo, I\'m using the new fs promises API";

try {
  await fs.writeFile(\'file1.txt\', data); // need to be in an async function
} catch (error) {
  console.log(error)
}