Robots Parser

NodeJS robots.txt parser.

It currently supports:

• User-agent:
• Allow:
• Disallow:
• Sitemap:
• Crawl-delay:
• Host:
• Paths with wildcards (*) and EOL matching ($)

Installation

Via NPM:

npm install npm install --save https://github.com/menno120/robots-parser

Usage

import robotsParser from "robots-parser";

var robots = new Robots('http://www.example.com/robots.txt', [
	'User-agent: *',
	'Disallow: /dir/',
	'Disallow: /test.html',
	'Allow: /dir/test.html',
	'Allow: /test.html',
	'Crawl-delay: 1',
	'Sitemap: http://example.com/sitemap.xml',
	'Host: example.com'
].join('\n'));

robots.isAllowed('http://www.example.com/test.html', 'Sams-Bot/1.0'); // false
robots.isAllowed('http://www.example.com/dir/test.html', 'Sams-Bot/1.0'); // true
robots.isDisallowed('http://www.example.com/dir/test2.html', 'Sams-Bot/1.0'); // true
robots.getCrawlDelay('Sams-Bot/1.0'); // 1
robots.getSitemaps(); // ['http://example.com/sitemap.xml']
robots.getPreferedHost(); // example.com

isAllowed(url, [ua])

boolean or undefined

Returns true if crawling the specified URL is allowed for the specified user-agent.

This will return undefined if the URL isn't valid for this robots.txt.

isDisallowed(url, [ua])

boolean or undefined

Returns true if crawling the specified URL is not allowed for the specified user-agent.

This will return undefined if the URL isn't valid for this robots.txt.

getMatchingLineNumber(url, [ua])

number or undefined

Returns the line number of the matching directive for the specified URL and user-agent if any.

Line numbers start at 1 and go up (1-based indexing).

Returns -1 if there is no matching directive. If a rule is manually added without a lineNumber then this will return undefined for that rule.

getCrawlDelay([ua])

number or undefined

Returns the number of seconds the specified user-agent should wait between requests.

Returns undefined if no crawl delay has been specified for this user-agent.

getSitemaps()

array

Returns an array of sitemap URLs specified by the sitemap: directive.

getPreferredHost()

string or null

Returns the preferred host name specified by the host: directive or null if there isn't one.

Changes

Version 1.0.0:

• Initial release.

License

The MIT License (MIT)

Copyright (c) 2014 Sam Clarke

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.