Solution to PHP Fatal error: Call to undefined function imagecreate()

When you use PHP's image processing function, if the error message "PHP Fatal error: Call to undefined function imagecreate()" appears, it means that your PHP does not have the GD extension installed. The GD extension is a commonly used extension in PHP image processing. It provides a series of functions to operate images.

The solution to this problem is very simple, just install the GD extension. While installation methods may vary depending on your operating system and PHP version, the methods provided here should work for most situations.

1. Check the system and PHP version

Before installing the GD extension, you first need to check the system and PHP version. You can use the following command to view:

$ lsb_release -a      // 查看操作系统版本
$ php -v              // 查看PHP版本

2. Install GD extension

You can install GD extension through the following steps:

• Debian/ Ubuntu system

$ sudo apt-get install php-gd

• CentOS/Fedora system

$ sudo yum install php-gd

• macOS system

If you use the macOS operating system, You can use the following command to install:

$ brew install php-gd

• Manual installation

If you do not use a package manager or need to install manually, you can follow the steps below:

1. Download the GD extension source code, which can be downloaded from PECL (http://pecl.php.net/package/gd).
2. Extract the source code file:

$ tar zxvf gd-x.x.x.tar.gz

3. Enter the decompressed directory:

$ cd gd-x.x.x

4. Compile and install the extension:

$ phpize
$ ./configure
$ make
$ make install

Before compiling, please make sure you have installed the tools and dependent libraries required for PHP development, such as gcc, make, autoconf, etc.

3. Restart the Web server

After installing the GD extension, you need to restart the Web server to make it take effect. You can use the following command to restart Apache or Nginx:

• Apache Server

$ sudo service apache2 restart

• Nginx Server

$ sudo service nginx restart

4. Verify whether the installation is successful

You can create a simple PHP file to verify whether the installation is successful:

<?php
if(function_exists('imagecreate'))
{
    echo 'GD扩展已安装！';
} else {
    echo 'GD扩展未安装！';
}
?>

If the output is "GD extension has been installed!", then it means Successful installation.

Summary

"PHP Fatal error: Call to undefined function imagecreate()" is caused by PHP not installing the GD extension. This problem can be solved by installing the GD extension. Installation methods may vary depending on your operating system and PHP version, but the methods we provide will work in most cases.

The above is the detailed content of Solution to PHP Fatal error: Call to undefined function imagecreate(). For more information, please follow other related articles on the PHP Chinese website!