README

Robots.txt parser

An easy to use, extensible robots.txt parser library with full support for literally every directive and specification on the Internet.

Usage cases:

• Permission checks
• Fetch crawler rules
• Sitemap discovery
• Host preference
• Dynamic URL parameter discovery
• robots.txt rendering

Advantages

(compared to most other robots.txt libraries)

• Automatic robots.txt download. (optional)
• Integrated Caching system. (optional)
• Crawl Delay handler.
• Documentation available.
• Support for literally every single directive, from every specification.
• HTTP Status code handler, according to Google's spec.
• Dedicated User-Agent parser and group determiner library, for maximum accuracy.
• Provides additional data like preferred host, dynamic URL parameters, Sitemap locations, etc.
• Protocols supported: HTTP, HTTPS, FTP, SFTP and FTP/S.

Requirements:

• PHP 7.3+ or 8.0+
• PHP extensions:
  • cURL
  • mbstring

Installation

The recommended way to install the robots.txt parser is through Composer. Add this to your composer.json file:

{
  "require": {
    "vipnytt/robotstxtparser": "^2.1"
  }
}

Then run: php composer update

Getting started

Basic usage example

<?php
$client = new vipnytt\RobotsTxtParser\UriClient('http://example.com');

if ($client->userAgent('MyBot')->isAllowed('http://example.com/somepage.html')) {
    // Access is granted
}
if ($client->userAgent('MyBot')->isDisallowed('http://example.com/admin')) {
    // Access is denied
}

A small excerpt of basic methods

<?php
// Syntax: $baseUri, [$statusCode:int|null], [$robotsTxtContent:string], [$encoding:string], [$byteLimit:int|null]
$client = new vipnytt\RobotsTxtParser\TxtClient('http://example.com', 200, $robotsTxtContent);

// Permission checks
$allowed = $client->userAgent('MyBot')->isAllowed('http://example.com/somepage.html'); // bool
$denied = $client->userAgent('MyBot')->isDisallowed('http://example.com/admin'); // bool

// Crawl delay rules
$crawlDelay = $client->userAgent('MyBot')->crawlDelay()->getValue(); // float | int

// Dynamic URL parameters
$cleanParam = $client->cleanParam()->export(); // array

// Preferred host
$host = $client->host()->export(); // string | null
$host = $client->host()->getWithUriFallback(); // string
$host = $client->host()->isPreferred(); // bool

// XML Sitemap locations
$host = $client->sitemap()->export(); // array

The above is just a taste the basics, a whole bunch of more advanced and/or specialized methods are available for almost any purpose. Visit the cheat-sheet for the technical details.

Visit the Documentation for more information.

Directives

• Clean-param
• Host
• Sitemap
• User-agent
  • Allow
  • Cache-delay
  • Comment
  • Crawl-delay
  • Disallow
  • NoIndex
  • Request-rate
  • Robot-version
  • Visit-time

Specifications

• Google robots.txt specifications
• Yandex robots.txt specifications
• W3C Recommendation HTML 4.01 specification
• Sitemaps.org protocol
• Sean Conner: "An Extended Standard for Robot Exclusion"
• Martijn Koster: "A Method for Web Robots Control"
• Martijn Koster: "A Standard for Robot Exclusion"
• RFC 7231, 2616
• RFC 7230, 2616
• RFC 5322, 2822, 822
• RFC 3986, 1808
• RFC 1945
• RFC 1738
• RFC 952