PHP pathinfo Function

last modified April 3, 2025

The PHP pathinfo function returns information about a file path. It can extract the directory name, filename, and extension components.

Basic Definition

The pathinfo function parses a path and returns an associative array or string with the components. It takes two parameters: the path and optional flags.

Syntax: pathinfo(string $path, int $flags = PATHINFO_ALL): mixed. The flags parameter determines which components to return.

Basic pathinfo Example

This shows the simplest usage of pathinfo to get all components.

basic_pathinfo.php

<?php

declare(strict_types=1);

$path = "/var/www/html/index.php";
$info = pathinfo($path);

print_r($info);

This returns an array with all path components. The dirname is the directory, basename is the full filename, and extension is the file extension.

Getting Specific Components

You can request specific components using the flags parameter.

specific_components.php

<?php

declare(strict_types=1);

$path = "/var/www/html/index.php";

$dirname = pathinfo($path, PATHINFO_DIRNAME);
$basename = pathinfo($path, PATHINFO_BASENAME);
$extension = pathinfo($path, PATHINFO_EXTENSION);
$filename = pathinfo($path, PATHINFO_FILENAME);

echo "Dir: $dirname\n";       // /var/www/html
echo "Base: $basename\n";     // index.php
echo "Ext: $extension\n";     // php
echo "File: $filename\n";     // index

Each flag returns just one component as a string. This is more efficient than getting the full array when you only need one part.

Windows Path Example

pathinfo works with Windows paths using backslashes.

windows_path.php

<?php

declare(strict_types=1);

$path = "C:\\Windows\\System32\\kernel32.dll";
$info = pathinfo($path);

print_r($info);

The function correctly handles Windows-style paths. It returns components regardless of the directory separator style used in the input.

URL Path Example

pathinfo can also parse URL paths to extract components.

url_path.php

<?php

declare(strict_types=1);

$url = "https://example.com/images/logo.png";
$info = pathinfo($url);

print_r($info);

This extracts components from the URL path. Note that pathinfo doesn't validate URLs - it processes them as strings.

Files Without Extensions

The function handles files without extensions correctly.

no_extension.php

<?php

declare(strict_types=1);

$path = "/home/user/docs/README";
$info = pathinfo($path);

print_r($info);

For files without extensions, the extension key is not present in the array. The filename and basename are identical.

Edge Cases

pathinfo has some interesting behaviors with edge cases.

edge_cases.php

<?php

declare(strict_types=1);

$path1 = "/var/www/html/";
$path2 = "/var/www/html";
$path3 = "filename.txt";

print_r(pathinfo($path1));
print_r(pathinfo($path2));
print_r(pathinfo($path3));

With directory paths, basename returns the directory name. For simple filenames, it returns just the filename. Trailing slashes are ignored.

Best Practices

Validate Input: Check paths exist before processing.
Handle Encoding: Be aware of character encoding in paths.
Security: Sanitize input when using in filesystem operations.
Performance: Use flags when you only need specific components.
Cross-platform: Works with both Unix and Windows paths.

Source

PHP pathinfo Documentation

This tutorial covered the PHP pathinfo function with practical examples showing its usage in different scenarios.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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