PHPCompatibilityChecking

This sample project is designed to validate the compatibility of PHP files in your server folder.

Requirements

• PHP 5.4+
• Composer

PHP_CodeSniffer requires PHP version 5.4.0 or greater Since this project was created through Composer, you should install Composer before starting this.

🗂 Step 1 - Create Project

As the first step, you'll need to create a project folder.

sudo mkdir php_compatibility
cd php_compatibility

📝 Step 2 - Create composer.json manually

Then create a composer.json file inside your project folder.

nano composer.json

Then paste the following content:

{
  "name": "yourname/php-compat-check",
  "description": "Project to check PHP 8 compatibility",
  "require-dev": {
    "squizlabs/php_codesniffer": "*",
    "dealerdirect/phpcodesniffer-composer-installer": "^0.7.2",
    "phpcompatibility/php-compatibility": "*"
  },
  "config": {
    "platform": {
      "php": "8.0"
    },
    "allow-plugins": {
      "dealerdirect/phpcodesniffer-composer-installer": true
    }
  },
  "minimum-stability": "dev",
  "prefer-stable": true
}

📥 Step 3 - Install Dependencies

Run this in the same folder:

composer install

This will

• Install PHP_CodeSniffer (Linter that checks PHP code style and compatibility)
• Install PHPCompatibility (A set of rules for checking PHP version compatibility)
• Install PHPCSUtils and required plugins
• Register the PHPCompatibility standard automatically

✅ Step 4 - Run PHP 8 Compatibility Check

Run this in the same folder

./vendor/bin/phpcs --standard=PHPCompatibility --runtime-set testVersion 8.0 /path/to/your/php/files

Output of Compatibility Check

Once you've set everything up and run the compatibility check, the output of phpcs will list errors and warnings in your PHP code that are not compatible with PHP 8.0.

FILE: /var/www/html/myapp/test.php
-----------------------------------------------------------------------------------------------------
FOUND 2 ERRORS AND 1 WARNING AFFECTING 3 LINES
-----------------------------------------------------------------------------------------------------
  12 | ERROR   | Function each() is deprecated since PHP 7.2 and removed in PHP 8.0
  25 | WARNING | The create_function() function is deprecated since PHP 7.2 and removed in PHP 8.0
  40 | ERROR   | The implode() function's parameter order changed in PHP 7.4
-----------------------------------------------------------------------------------------------------

🔍 What the Output Tells You

• Line number: Where the issue occurs
• Type: ERROR (incompatible with PHP 8) or WARNING (may cause issues)
• Message: What’s wrong and which PHP version introduced the change

Customize the output

• Show only errors (suppress warnings):

./vendor/bin/phpcs --standard=PHPCompatibility --runtime-set testVersion=8.0 -n /path

• Output in summary format:

./vendor/bin/phpcs -s --standard=PHPCompatibility --runtime-set testVersion=8.0 /path

• Save output to a report:

./vendor/bin/phpcs --standard=PHPCompatibility --report=full > report.txt

• exclude certain folders. You can use wildcards (*) in folder names:

./vendor/bin/phpcs
--standard=PHPCompatibility
--runtime-set testVersion=8.0
--ignore=/path/to/ignore1/*,/path/to/ignore2/*
/path/to/scan

• If you're in your project root and want to ignore, for example, the vendor/ and tests/ folders:

./vendor/bin/phpcs --standard=PHPCompatibility --runtime-set testVersion=8.0 --ignore=vendor/*,tests/* ./

🧪 Example: You have 70 folders inside /home/user/web/, and each of them contains a subfolder named data/, which you want to exclude from the PHP 8 compatibility scan.

./vendor/bin/phpcs \
  --standard=PHPCompatibility \
  --runtime-set testVersion=8.0 \
  --ignore=*/data/* \
  /home/gayan/web/

🔍 Explanation:

• --ignore=*/data/* matches any path ending with /data/, no matter how deep it is.
• It effectively skips:
  • /home/user/web/project1/data/
  • /home/user/web/project2/data/
  • ...
  • /home/user/web/project70/data/
• Exclude multiple patterns (example)

--ignore=*/data/*,*/cache/*,*/tmp/*

• If you just want to verify what would be scanned, add -s for a summary or -v for verbose mode:

./vendor/bin/phpcs -s -v
--standard=PHPCompatibility
--runtime-set testVersion=8.0
--ignore=*/data/*
/home/gayan/web/

Reference

• https://aureatelabs.com/blog/how-to-check-your-code-is-compatible-with-php/
• https://github.com/PHPCompatibility/PHPCompatibility
• https://github.com/PHPCSStandards/PHP_CodeSniffer/

License

This code is released under the GNU Lesser General Public License (LGPL). For more information, visit http://www.gnu.org/copyleft/lesser.html