Introducing curling, a simple node wrapper for curl.

Published on Jan 01, 2013

Another of those libraries that I’m tired to write again and again, so here it goes, up to npm.

It has a very simple API that exports only two methods connect and run.

Install or get the code.

  npm install curling

Or download the code from github

run(command, cb)

You shouldn’t have to use run but is in there just as a convenience or if you need to do something crazy that is not possible to do via the connection object.

It pretty much allow you to send any command with any option to curl. It used internally by connect and the connection object.

  var curl = require('curling');"--GET", function (err, result) {
    console.log(result.payload); // should output the html for the cnn page to console.
    console.log(result.stats);   // should output some of the statistics on downloading the page



This method takes an options object with general options that will be re-used in each command.

  var options = {user: "hernan:secret"};

It returns a connection object.

Connection object API

It has five methods, each corresponding to an HTTP verb. They all have the same signature: method(url, options, cb). The method are:

  • head();
  • get();
  • post();
  • put();
  • del(); //DELETE

The callback takes two parameters cb(err, result) where the result is a curl-result object.


It has two properties, payload and stats. The payload contains the data returned in the stdout by curl while the stats is an object that parse as the content of stderr.

Stats is of the form:

{ totalSize: 0, received: 0, xferd: 0, averageDownloadSpeed: 0, averageUploadSpeed: 0, totalTime: 0, timeSpent: 0, timeLeft: 0, currentSpeed: ‘0 Kb’ }

The time properties are converted to milliseconds, the rest of the properties are of type Number in the same units as returned by curl except for the currentSpeed that is a string with the unit at the end (again as returned by curl).

Passing options.

There are two ways to pass options and data to a request.
You can use the options for the connect method and this options will be used in each and every request.
You can also use the options object in each of the verb methods.

The options object is actually a hash where the keys should be the name of the flag in a curl command, for example to set an Accept header and pass some data you could pass an options as the following.

var options = { header: “Accept: text/html”, data: [“name=hernan”, “last=garcia”] };

The keys in an options object can be one of the following types, String, Array or null.

Strings are useful when you only need to set a single value, arrays are used to pass multiple values, like data, header and so. Null is a special case and is used for empty flags, like —false.