PHP basename Function
PHP basename function tutorial shows how to extract filenames from paths in PHP. Learn basename with practical examples.
PHP basename Function
last modified April 3, 2025
The PHP basename function extracts the filename component from a path string. It’s useful for working with file paths in a cross-platform way.
Basic Definition
The basename function returns the trailing name component of a path. It takes two parameters: the path string and an optional suffix to remove.
Syntax: basename(string $path, string $suffix = “”): string. The function is binary-safe and works with both Unix and Windows paths.
Basic basename Example
This shows the simplest usage of basename to extract a filename.
basic_basename.php
<?php
declare(strict_types=1);
$path = “/var/www/html/index.php”; $filename = basename($path);
echo $filename; // Outputs: index.php
This extracts “index.php” from the full path. The function works the same regardless of the directory separator used in the input path.
Removing File Extension
The second parameter can remove a specified suffix from the result.
basename_suffix.php
<?php
declare(strict_types=1);
$path = “/var/www/html/index.php”; $filename = basename($path, “.php”);
echo $filename; // Outputs: index
Here we remove the “.php” extension from the result. Note that the suffix must match exactly, including case sensitivity on case-sensitive filesystems.
Windows Path Example
basename works with Windows paths using backslashes.
windows_path.php
<?php
declare(strict_types=1);
$path = “C:\Windows\System32\kernel32.dll”; $filename = basename($path);
echo $filename; // Outputs: kernel32.dll
The function correctly handles Windows-style paths. It returns “kernel32.dll” regardless of the directory separator style used in the input.
URL Path Example
basename can also extract the last component from URLs.
url_path.php
<?php
declare(strict_types=1);
$url = “https://example.com/images/logo.png"; $filename = basename($url);
echo $filename; // Outputs: logo.png
This extracts “logo.png” from the URL. Note that basename doesn’t validate URLs - it just processes them as strings.
Multiple Directory Levels
The function works with paths containing multiple directory levels.
multi_level.php
<?php
declare(strict_types=1);
$path = “/home/user/docs/projects/php/README.md”; $filename = basename($path);
echo $filename; // Outputs: README.md
Despite multiple directory levels, basename correctly returns just “README.md”. It only looks at the last path component.
Edge Cases
basename has some interesting behaviors with edge cases.
edge_cases.php
<?php
declare(strict_types=1);
$path1 = “/var/www/html/”; $path2 = “/var/www/html”; $path3 = “filename.txt”;
echo basename($path1); // Outputs: html echo basename($path2); // Outputs: html echo basename($path3); // Outputs: filename.txt
With directory paths (ending with separator), it returns the directory name. For simple filenames, it returns the filename unchanged. Trailing slashes are ignored.
Best Practices
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Validate Input: Check paths exist before processing.
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Handle Encoding: Be aware of character encoding in paths.
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Security: Sanitize input when using in filesystem operations.
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Cross-platform: Use for both Unix and Windows paths.
Source
This tutorial covered the PHP basename 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.
