markdown-link-check

markdown-link-check

Extracts links from markdown texts and checks whether each link is alive (200 OK) or dead. mailto: links are validated with isemail.

Installation

To add the module to your project, run:

npm install --save markdown-link-check

To install the command line tool globally, run:

npm install -g markdown-link-check

---

Run using Docker

Build a Docker image:

docker build --tag markdown-link-check .

Pipe your README.md file to docker run:

docker run --rm -i markdown-link-check < README.md

API

markdownLinkCheck(markdown, [opts,] callback)

Given a string containing markdown formatted text and a callback, extract all of the links and check if they're alive or dead. Call the callback with (err, results)

Parameters:

• markdown string containing markdown formatted text.
• opts optional options object containing any of the following optional fields:
  • baseUrl the base URL for relative links.
  • showProgressBar enable an ASCII progress bar.
  • httpHeaders to apply URL specific headers, see example below.
• callback function which accepts (err, results).
  • err an Error object when the operation cannot be completed, otherwise null.
  • results an array of objects with the following properties:
    • link the link provided as input
    • status a string set to either alive or dead.
    • statusCode the HTTP status code. Set to 0 if no HTTP status code was returned (e.g. when the server is down).
    • err any connection error that occurred, otherwise null.

Examples

Module

Basic usage:

'use strict';

var markdownLinkCheck = require('markdown-link-check');

markdownLinkCheck('[example](http://example.com)', function (err, results) {
    if (err) {
        console.error('Error', err);
        return;
    }
    results.forEach(function (result) {
        console.log('%s is %s', result.link, result.status);
    });
});

With options, for example using URL specific headers:

'use strict';

var markdownLinkCheck = require('markdown-link-check');

markdownLinkCheck('[example](http://example.com)', { httpHeaders: [{ urls: ['http://example.com'], headers: { 'Authorization': 'Basic Zm9vOmJhcg==' }}] }, function (err, results) {
    if (err) {
        console.error('Error', err);
        return;
    }
    results.forEach(function (result) {
        console.log('%s is %s', result.link, result.status);
    });
});

Command Line Tool

The command line tool optionally takes 1 argument, the file name or http/https URL. If not supplied, the tool reads from standard input.

Check links from a markdown file hosted on the web

markdown-link-check https://github.com/tcort/markdown-link-check/blob/master/README.md

Check links from a local markdown file

markdown-link-check ./README.md

Check links from a local markdown folder (recursive)

find . -name \*.md -exec markdown-link-check {} \;

Check links from standard input

cat *.md | markdown-link-check

Usage

  Usage: markdown-link-check [options] [filenameOrUrl]

  Options:

    -h, --help             output usage information
    -p, --progress         show progress bar
    -c, --config [config]  apply a config file (JSON), holding e.g. URL specific header configuration

Config file format

config.json:

{
    "httpHeaders": [
        {
            "urls": [
                "https://example.com"
            ],
            "headers": {
                "Authorization": "Basic Zm9vOmJhcg==",
                "Foo": "Bar"
            }
        }
    ]
}

httpHeaders: The headers are only applied to links where the link starts with one of the supplied URLs in the urls section.

Testing

npm test

License

See LICENSE.md

Changelog

Version 3.4.0

• support for providing custom HTTP headers