Check if a path is a directory or a file

The is_dir function returns whether the argument is a directory, while is_file returns whether the argument is a file. Use file_exists to check if it is either.

$dir  = "/this/is/a/directory";
$file = "/this/is/a/file.txt";

echo is_dir($dir) ? "$dir is a directory" : "$dir is not a directory", PHP_EOL,
    is_file($dir) ? "$dir is a file" : "$dir is not a file", PHP_EOL,
    file_exists($dir) ? "$dir exists" : "$dir doesn't exist", PHP_EOL,
    is_dir($file) ? "$file is a directory" : "$file is not a directory", PHP_EOL,
    is_file($file) ? "$file is a file" : "$file is not a file", PHP_EOL,
    file_exists($file) ? "$file exists" : "$file doesn't exist", PHP_EOL;

This gives:

/this/is/a/directory is a directory
/this/is/a/directory is not a file
/this/is/a/directory exists
/this/is/a/file.txt is not a directory
/this/is/a/file.txt is a file
/this/is/a/file.txt exists

Checking file type

Use filetype to check the type of a file, which may be:

• fifo
• char
• dir
• block
• link
• file
• socket
• unknown

Passing the filename to the filetype directly:

echo filetype("~"); // dir

Note that filetype returns false and triggers an E_WARNING if the file doesn’t exist.

Checking readability and writability

Passing the filename to the is_writable and is_readable functions check whether the file is writable or readable respectively.