Implementation of the difference comparison function of background configuration management

M66 2025-06-06

How to implement the difference comparison function in background configuration management? Use PHP's array_diff_uassoc function to compare configuration data

In background configuration management, especially when multiple environments and multiple versions are involved, the comparison of configuration files is a common and important task. Differential comparisons can help developers quickly discover configuration changes between different environments, and then make corresponding adjustments and optimizations. PHP provides some built-in functions to implement this function, where the array_diff_uassoc() function is a very useful tool that can compare the differences between two arrays based on key names and custom comparison functions.

This article will use a simple example to introduce how to use the array_diff_uassoc() function to implement differential comparison of configuration data.

1. Introduction to array_diff_uassoc() function

array_diff_uassoc() is a function in PHP used to compare two arrays. Unlike the common array_diff() , array_diff_uassoc() not only compares the values of an array, it also compares the keys of the array and allows us to define how to compare these keys and values through a custom comparison function.

Function prototype:

 array_diff_uassoc(array $array1, array $array2, callable $key_compare_func): array

$array1 : The first array, used for comparison.
$array2 : The second array, used to compare with the first array.
$key_compare_func : A custom callback function to compare keys of two arrays.

The return value is an array containing elements in the first array that are different from the second array.

2. How to compare configuration data?

Suppose we have two configuration files, one is the configuration of the production environment and the other is the configuration of the development environment. We want to compare the differences in these two configuration files. For simplicity, we represent two configuration files as PHP arrays.

 // Production environment configuration
$prodConfig = [
    'database_host' => 'db.m66.net',
    'database_user' => 'prod_user',
    'database_pass' => 'prod_pass',
    'debug' => false,
    'api_url' => 'https://api.m66.net',
];

// Development environment configuration
$devConfig = [
    'database_host' => 'db.m66.net',
    'database_user' => 'dev_user',
    'database_pass' => 'dev_pass',
    'debug' => true,
    'api_url' => 'https://dev-api.m66.net',
];

In this example, $prodConfig is the configuration of the production environment and $devConfig is the configuration of the development environment. Our goal is to compare the differences in these two configuration arrays, especially those with different values.

3. Implement configuration data comparison

First, we need to define a custom key comparison function. The function of this function is to allow us to compare two keys according to our needs. If you simply compare keys literally, this function will be very simple.

 // Custom comparison functions
function compareKeys($key1, $key2) {
    return strcmp($key1, $key2);
}

Next, we can use the array_diff_uassoc() function to compare configuration arrays for production and development environments.

 // Get the difference in the configuration file
$diff = array_diff_uassoc($prodConfig, $devConfig, 'compareKeys');

// Output difference
echo "Configuration Differences：\n";
print_r($diff);

This code outputs configuration items that are different in production and development environments. array_diff_uassoc() compares the keys of the array through the compareKeys() function and returns items with the same key names but different values in the two arrays.

4. Sample output

Suppose we run the above code, the output is as follows:

 Configuration Differences：
Array
(
    [database_user] => prod_user
    [database_pass] => prod_pass
    [debug] => false
    [api_url] => https://api.m66.net
)

From the output results, we can see that database_user , database_pass , debug and api_url are configuration items that differ in production and development environments. We can make corresponding adjustments based on these differences to ensure consistency and correctness of the configuration files.

5. Summary

By utilizing PHP's array_diff_uassoc() function, we can easily implement the differential comparison function of configuration data. This approach is very suitable for multi-environment or multi-version management scenarios, helping developers quickly locate differences in configurations and make corresponding adjustments. You can adjust the custom comparison function according to actual needs to meet more complex needs.

Hope this article helps you better understand how to use PHP to compare configuration files.

array_diff_uassoc