PHP Files and Directories

Published 4 years ago.
Last updated August 4th, 2020

Include a file

• Include local files using the include() or require() methods. Both methods are the same except for the fact that require() produces a fatal error if it fails while include() only produces a warning.

include('../my_file.php');

Get the current file path

// Get the absolute path to the directory containing the current working file.
$dir_path = __DIR__; // Recommended fastest way, but only available for PHP >= 5.3.
$dir_path = dirname(__FILE__);

Get parts of a file path

$file_path = '/home/mydir/myfile.pdf';

// Get all the path parts in an array.
$file_path_parts = pathinfo( $file_path );

// Get each part separately
echo pathinfo( $file_path, PATHINFO_DIRNAME); // Returns "/home/mydir"
echo pathinfo( $file_path, PATHINFO_BASENAME); // Returns "myfile.pdf"
echo pathinfo( $file_path, PATHINFO_EXTENSION); // Returns "pdf"
echo pathinfo( $file_path, PATHINFO_FILENAME); // Returns "myfile"

Get a file extension

This is faster than using pathinfo() or getting the value from array if you just need the ext.

$ext = substr(strrchr($filename, "."), 1);

Get the headers of a remote file

Get the headers from a file hosted at a remote server without downloading the whole file.
Headers contain content-type and file size info.

$media_file_headers = array_change_key_case(get_headers($file_url, TRUE));

Check if a local file exists

If you want to check exists and:

• Is only a file: Use is_file()
• Is only a dir: Use is_dir()
• Is file or dir: Use file_exists()

If you want to check exists and is readable:

• And is only file: Use is_file() and is_readable()
• And is only dir: Use is_dir() and is_readable()
• And is file or dir: Use is_readable()

You don’t need to use file_exists() and is_readable() together because is_readable() also checks if file_exists().

Pairing is_readable() with either is_file() or is_dir() is only to check if is readable specifically on a file only or specifically on a directory only.

$filename = $_SERVER['DOCUMENT_ROOT'] . 'images/myImage.png';

if (file_exists($filename)) {
     echo "The file $filename exists";
} else {
     echo "The file $filename does not exist";
}

Parsing Directories

/**
 * Converts a nested directory tree into a multidimensional array
 * structured to represent the nesting hierarchy of all
 * files and directories defined by '$startpath'.
 */
function get_recursive_dir_file_listings( $startpath )
{
    $listings_array = array();

    $raw_listings = new RecursiveIteratorIterator(
        new RecursiveDirectoryIterator( $startpath ),
        RecursiveIteratorIterator::CHILD_FIRST
    );

    foreach ($raw_listings as $splFileInfo)
    {
        if( $splFileInfo->isDir() )
        {
            $path = array( $splFileInfo->getFilename() => array() );
        }
        else
        {
            $path = array( $splFileInfo->getFilename() ); 
        }

        for( $depth = $raw_listings->getDepth() - 1; $depth >= 0; $depth-- )
        {
           $path = array( $raw_listings->getSubIterator( $depth )->current()->getFilename() => $path ); 
        } 

        $listings_array = array_merge_recursive( $listings_array, $path ); 
    } 

    return $listings_array;
}

// Example:
// This will print an array containing the contents of
// the current directory and everything under it.

print_r( get_recursive_dir_file_listings( __DIR__ ) ) ;