CrontabValidator

A validator for crontab expressions.

Sources used to determine the allowed expressions:

• https://crontab.guru/
• https://en.wikipedia.org/wiki/Cron

Features

• Validation of crontab expressions like 6,21,36,51 7-23/1 * FEB-NOV/2 *.

Requirements

• PHP >= 7.1

Installation

composer require "hollodotme/crontab-validator"

Usage

Boolean validation

<?php declare(strict_types=1);

namespace MyVendor\MyProject;

use hollodotme\CrontabValidator\CrontabValidator;

$validator = new CrontabValidator();

if ( $validator->isExpressionValid( '6,21,36,51 7-23/1 * FEB-NOV/2 *' ) )
{
	echo 'Expression is valid.';
}
else
{
	echo 'Expression is invalid.';	
}

Guarding

<?php declare(strict_types=1);

namespace MyVendor\MyProject;

use hollodotme\CrontabValidator\CrontabValidator;
use hollodotme\CrontabValidator\Exceptions\InvalidExpressionException;

$validator = new CrontabValidator();

try 
{
	# => All fine, execution continues
	$validator->guardExpressionIsValid( '6,21,36,51 7-23/1 * FEB-NOV/2 *' );
	
	# => This will raise an InvalidExpressionException
	$validator->guardExpressionIsValid( 'this is not a valid interval' );
}
catch ( InvalidExpressionException $e )
{
	echo $e->getMessage();
}

Prints:

Invalid crontab expression: "this is not a valid interval"

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Feedback and contributions welcome!