PHP Configuration

PHP can be configured using:

1. php.ini file – The main configuration file for PHP.
2. phpinfo() function – Displays current PHP configuration.
3. Web server integration – Apache, Nginx, or IIS may have additional PHP settings.

Finding php.ini

• Windows (XAMPP/WAMP): C:\xampp\php\php.ini
• Linux (LAMP): /etc/php/8.1/apache2/php.ini (version may vary)
• Mac (MAMP): /Applications/MAMP/bin/php/php7.x.x/conf/php.ini

You can find the loaded php.ini file using PHP:

<?php
phpinfo();
?>

• Open the page in a browser.
• Look for "Loaded Configuration File" – this shows the path to the active php.ini.

Important PHP Settings

1️⃣ Display Errors

display_errors = On    ; Show errors in browser (useful for development)
display_startup_errors = On
error_reporting = E_ALL

• On during development, Off in production for security.

2️⃣ Maximum File Upload Size

upload_max_filesize = 10M
post_max_size = 20M

• upload_max_filesize → Maximum single file size
• post_max_size → Maximum size for entire form submission

3️⃣ Timezone Setting

date.timezone = "Asia/Kolkata"

• Prevents errors when using date functions.
• Replace "Asia/Kolkata" with your timezone (see PHP manual for full list).

4️⃣ Maximum Execution Time

max_execution_time = 30   ; seconds

• Limits script execution time to avoid hanging.

5️⃣ Memory Limit

memory_limit = 128M

• Maximum memory a PHP script can use.

6️⃣ Extensions

Enable extensions by removing ; before the line in php.ini:

extension=mysqli
extension=curl

Checking PHP Configuration

Using phpinfo()

<?php
phpinfo();
?>

• Shows PHP version, extensions, server info, and all config values.

Using ini_get() and ini_set()

<?php
// Get current value
echo ini_get('max_execution_time'); // 30

// Change value at runtime
ini_set('max_execution_time', 60);
echo ini_get('max_execution_time'); // 60
?>

Note: Changes with ini_set() last only for the current script.

Changing PHP Configuration

• Edit php.ini – Permanent change
• .htaccess file (Apache only) – Temporary change for a directory:

php_value upload_max_filesize 20M
php_value post_max_size 25M

• Runtime with ini_set() – Temporary for a script

PHP Configuration Best Practices

• Development vs Production:
• display_errors = On for dev
• display_errors = Off for live site
• Security:
• Disable dangerous functions: exec, shell_exec, etc.
• Set proper file_uploads and open_basedir.
• Performance:
• Adjust memory_limit and max_execution_time for heavy scripts.
• Enable caching extensions like OPcache.

Practice Example: Check PHP Configuration

<?php
echo "<h2>PHP Configuration</h2>";

// PHP Version
echo "PHP Version: " . phpversion() . "<br>";

// Max Execution Time
echo "Max Execution Time: " . ini_get('max_execution_time') . " seconds<br>";

// Memory Limit
echo "Memory Limit: " . ini_get('memory_limit') . "<br>";

// Check if mysqli extension is loaded
if(extension_loaded('mysqli')){
    echo "MySQLi extension is enabled.";
} else {
    echo "MySQLi extension is not enabled.";
}
?>

This script displays:

• PHP version
• Maximum execution time
• Memory limit
• Whether MySQLi extension is enabled

✅ Key Points:

• php.ini is the main configuration file for PHP.
• Use phpinfo() to check current settings.
• Important settings: display_errors, upload_max_filesize, memory_limit, timezone.
• Extensions provide additional functionality, enable them as needed.
• Use ini_set() or .htaccess for script-specific adjustments.