The fs.ftruncate method in node.js USES the instructions

Method description:

File content interception operation.

Grammar:

fs.ftruncate(fd, len, [callback(err)])

Since this method belongs to the fs module, the fs module (var fs= require(" fs ")) needs to be introduced before use.

Receiving parameters:

Path                    The file path

Len                          Truncate the length, leaving only the characters within the length of the character, and the excess will be cleared.

Callback          Callback, passing an exception parameter err

Example:

var fs = require('fs');

fs.ftruncate('126.txt', 2, function(err){

 if(err){

  throw err;

 }

 console.log(' File content truncated successfully ');

})

Source:

fs.ftruncate = function(fd, len, callback) {

  if (util.isFunction(len)) {

    callback = len;

    len = 0;

  } else if (util.isUndefined(len)) {

    len = 0;

  }

  binding.ftruncate(fd, len, makeCallback(callback));

};