show_source() function in PHP

The show_source() function in PHP displays the source code of a PHP file with syntax highlighting. This function is useful for code documentation, debugging, or educational purposes where you need to display formatted PHP source code.

Syntax

show_source(file, return)

Parameters

• file − The file name to display. This can be a relative or absolute path to the PHP file.

• return − Optional boolean parameter. If set to true, the function returns the highlighted code as a string instead of printing it. Default is false.

Return Value

If the return parameter is true, it returns the syntax-highlighted code as a string. Otherwise, it outputs the highlighted code directly and returns true on success or false on failure.

Example 1: Displaying File Source

Here's how to use show_source() to display a PHP file with syntax highlighting ?

<?php
    // Display source code of current file
    show_source(__FILE__);
?>

Example 2: Returning Highlighted Code

Using the return parameter to get highlighted code as a string ?

<?php
    // Get highlighted code as string
    $highlighted = show_source("example.php", true);
    
    // Now you can manipulate or store the highlighted code
    echo "Code length: " . strlen($highlighted) . " characters";
    echo $highlighted;
?>

Key Points

• The function requires the target file to exist and be readable
• Output includes HTML tags with CSS classes for syntax highlighting
• Commonly used with highlight_file() which is an alias for this function
• The highlighted output uses predefined color schemes for different PHP syntax elements

Conclusion

The show_source() function is valuable for displaying PHP code with proper syntax highlighting. Use the return parameter when you need to process the highlighted output further rather than displaying it directly.