Retrieve File Name and Line Number in PHP

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Retrieve File Name and Line Number in PHP


When working with PHP, it's essential to have the ability to retrieve information about functions, such as the file name and line number where they are declared. One way to achieve this is by utilizing the built-in PHP class called ReflectionFunction. In this article, we will explore how to use the ReflectionFunction class to obtain relevant information about functions in PHP.

Using the ReflectionFunction Class:

The ReflectionFunction class is a powerful tool provided by PHP that allows developers to access various details about functions in their code. Below is an example demonstrating how to use the ReflectionFunction class to retrieve the file name and starting line number of a specific function.

Sometimes when developing PHP in large applications searching for function (without IDE) in all the files becomes boring. So I was looking for a quick solution to this. By searching few minutes I found a great solution.

Example: Retrieving File Name and Line Number

// Create a new instance of ReflectionFunction, targeting the 'selected' function
$r = new ReflectionFunction('selected');

// Obtain and display the file name where the function is declared
echo $file = $r->getFileName(); // getFileName() is an inherited method

// Obtain and display the starting line number of the function's declaration
echo $startLine = $r->getStartLine(); // getStartLine() is an inherited method

Exploring More Features

The ReflectionFunction class offers a range of capabilities beyond retrieving file names and line numbers. Developers can utilize this class to obtain comprehensive insights into functions, including their parameters, return types, and more. By leveraging the power of ReflectionFunction, developers can enhance their debugging and analysis processes.


In PHP development, having access to detailed information about functions is crucial for effective debugging and analysis. The ReflectionFunction class provides a convenient way to retrieve essential details such as file names and line numbers associated with functions. By incorporating ReflectionFunction into their development workflow, programmers can streamline their debugging efforts and gain valuable insights into their codebase.

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