Perform curl request in javascript?

You can use JavaScripts Fetch API (available in your browser) to make network requests.

If using node, you will need to install the node-fetch package.

const url = "https://api.wit.ai/message?v=20140826&q=";

const options = {
  headers: {
    Authorization: "Bearer 6Q************"
  }
};

fetch(url, options)
  .then( res => res.json() )
  .then( data => console.log(data) );

Yes, use getJSONP. It's the only way to make cross domain/server async calls. (*Or it will be in the near future). Something like

$.getJSON('your-api-url/validate.php?'+$(this).serialize+'callback=?', function(data){
if(data)console.log(data);
});

The callback parameter will be filled in automatically by the browser, so don't worry.

On the server side ('validate.php') you would have something like this

<?php
if(isset($_GET))
{
//if condition is met
echo $_GET['callback'] . '(' . "{'message' : 'success', 'userID':'69', 'serial' : 'XYZ99UAUGDVD&orwhatever'}". ')';
}
else echo json_encode(array('error'=>'failed'));
?>

Since you can use Javascript in two different place: Client and Server, I'll try to share for both.

First for client usage:
Javascript has native Ajax support, with XMLHTTPRequest (but it's harder to work with)

var xhr = new XMLHttpRequest();
xhr.open("GET", "http://example.com/api/data", true);
xhr.onreadystatechange = function() {
  if (xhr.readyState === 4 && xhr.status === 200) {
    console.log(xhr.responseText);
  }
};
xhr.send();

I would use Fetch API instead, as it's more friendly:

fetch('http://example.com/api/data')
  .then(response => {
    if (!response.ok) {
      throw new Error('Network response was not ok');
    }
    return response.json();
  })
  .then(data => console.log(data))
  .catch(error => console.error('Fetch error:', error));

Now for the server:
you have several options for running cURL in javascript/NodeJs,

1. Using exec command, to execute a command, including cURL
2. Using node-libcurl, as a binding to the libcurl API
3. Use the alternative with the same goal! As the goal for cURL is request to HTTP, we have several options here, including:

• request
• build in HTTPS
• got
• needle
• etc..

I wrote more about this here: How to use cuRL in Javascript and it's alternative., feel free to read.

Example for exec comamnd

const { exec } = require('child_process');

exec('curl -s https://example.com', (error, stdout, stderr) => {
  if (error) {
    console.error(`Error: ${error}`);
    return;
  }
  if (stderr) {
    console.error(`stderr: ${stderr}`);
    return;
  }
  console.log(`stdout: ${stdout}`);
});

Example for node-libcurl

const { curly } = require('node-libcurl');

async function run() {
  const { statusCode, data, headers } = await curly.get('https://www.google.com')
  
  console.log(statusCode)
  console.log('---')
  console.log(data)
}

run();

Example for Axios (as an alternative)

const axios = require('axios');
const fs = require('fs');

Axios.get('https://example.com')
    .then(response => {
        fs.writeFile('index.html', response.data, (err) => {
            if (err) {
                console.error('Error writing file:', err);
            } else {
                console.log('File saved as index.html');
            }
        });
    })
    .catch(error => {
        console.error('Error fetching URL

 :', error);
});

I hope it helps!

The currently accepted answer is for making ajax calls and you may have to deal with cross-site issues.

But if you're just wanting to run Linux curl on the server-side, as you do with PHP, then you can use this.

Here is my function to perform curl requests with nodejs.

It's a simple async function and no special packages outside of node are required. You can do what you want with the resulting data and error or return it to use in another async function.

I just logged for example.

const util = require('util');
const exec = util.promisify(require('child_process').exec);

const goCurl = async (url) => {
    const { stdout, stderr } = await exec(`curl '${url}'`);

    console.log('data:', stdout);
    console.error('err:', stderr);

}


const url = `https://static.canva.com/web/a7a51d4eae8626ead168.ltr.css`;
goCurl(url);