How To Enable GD Support In PHP On CentOS?

Checking Current GD Status

To check if GD support is enabled in your PHP installation, use this command:

php -i | grep -i --color gd

This command shows information about the GD module. If GD is not enabled, you'll see no output or a message that GD is not available.

GD Support => enabled
GD Version => 2.1.0

Installing GD and Required Packages

To enable GD support, install the necessary packages using the YUM package manager:

yum install gd gd-devel php-gd

This command installs the GD library, its development files, and the PHP-GD extension.

Restarting Apache Web Server

After installing the packages, restart the Apache web server to apply the changes. Restarting Apache reloads the PHP configuration, including the new GD extension.

Use this command to restart Apache:

service httpd restart

This command stops and starts the Apache service, making the new GD support available for your PHP applications.

Testing PHP GD Functions

To check if GD support works in PHP, create a PHP script to test GD functions. Here's a basic example:

<?php
// Check if GD is enabled
if (extension_loaded('gd')) {
    echo "GD is enabled. Version: " . gd_info()['GD Version'] . "\n";

    // Create a simple image
    $image = imagecreatetruecolor(100, 100);
    $backgroundColor = imagecolorallocate($image, 255, 0, 0);
    imagefill($image, 0, 0, $backgroundColor);

    // Save the image
    imagepng($image, 'test_image.png');
    imagedestroy($image);

    echo "Test image created successfully.";
} else {
    echo "GD is not enabled.";
}
?>

Save this script as gd_test.php in your web server's document root and run it through your browser or command line.

To read the test results:

1. If GD is enabled, you'll see a message confirming this with the GD version.
2. The script will try to create a 100x100 pixel red image named test_image.png.
3. If the image is created, you'll see a confirmation message.
4. Look in your server's directory for the test_image.png file.

If you see the confirmation messages and the test image is created, GD support works in your PHP installation on CentOS.

<?php
$gd_functions = get_extension_funcs('gd');
if ($gd_functions) {
    echo "Available GD functions:\n";
    foreach ($gd_functions as $function) {
        echo "- $function\n";
    }
} else {
    echo "GD extension is not available.";
}
?>