phpinfo() outputs detailed PHP runtime configuration and extension information. This guide explains the function with focused examples and the decisions that matter in real applications.
What Is phpinfo() in PHP?
Outputs detailed PHP runtime configuration and extension information.
A typical call looks like this:
<?php
phpinfo([$flags]);
The input arguments shown in the call identify the relevant connection, resource, value, path or configuration for the operation. Pay attention to argument order and to the return value demonstrated below.
Example 1: Basic Usage
This first example uses phpinfo() directly to demonstrate its basic purpose.
<?php
phpinfo(INFO_GENERAL);
The returned value illustrates outputs detailed PHP runtime configuration and extension information. Never expose full phpinfo output publicly in production.
Example 2: A Different Input or Option
The next example changes the input or option, showing another supported use of phpinfo().
<?php
phpinfo(INFO_MODULES);
The returned value illustrates outputs detailed PHP runtime configuration and extension information. Never expose full phpinfo output publicly in production.
Practical Example: Applying the Function
In application code, phpinfo() belongs in a controlled workflow with input validation, a checked result and cleanup where needed.
<?php
ob_start(); phpinfo(INFO_CONFIGURATION); $information = ob_get_clean(); echo "Configuration bytes: " . strlen($information);
The returned value illustrates outputs detailed PHP runtime configuration and extension information. Never expose full phpinfo output publicly in production.
Important Behavior and Edge Cases
- Main behavior: Outputs detailed PHP runtime configuration and extension information.
- Important limitation: Never expose full phpinfo output publicly in production.
- Requirements: Check the runtime, file permissions and operating system when results depend on the environment.
Comparison With Related Functions
| Function or Approach | When to Use It |
|---|---|
phpinfo() | Outputs detailed PHP runtime configuration and extension information. |
ini_get | Reads one specific PHP configuration option rather than printing the full phpinfo report. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
Ignoring the specific limits or preconditions of phpinfo(). | Never expose full phpinfo output publicly in production. |
| Assuming every environment produces the same result. | Check the runtime, file permissions and operating system when results depend on the environment. |
Key Takeaways
- Outputs detailed PHP runtime configuration and extension information.
- Never expose full phpinfo output publicly in production.
- Check the runtime, file permissions and operating system when results depend on the environment.
Use phpinfo() when its behavior matches your task, and verify the relevant return value before taking further action. The output depends on the local configuration when it uses resources, files or an interactive terminal.