How to append to a file in Node?

Question

I am trying to append a string to a log file. However writeFile will erase the content each time before writing the string.

fs.writeFile(\'log.txt\'         


        

Answer 1

Here's a full script. Fill in your file names and run it and it should work! Here's a video tutorial on the logic behind the script.

var fs = require('fs');

function ReadAppend(file, appendFile){
  fs.readFile(appendFile, function (err, data) {
    if (err) throw err;
    console.log('File was read');

    fs.appendFile(file, data, function (err) {
      if (err) throw err;
      console.log('The "data to append" was appended to file!');

    });
  });
}
// edit this with your file names
file = 'name_of_main_file.csv';
appendFile = 'name_of_second_file_to_combine.csv';
ReadAppend(file, appendFile);