PHP pathinfo function

The PHP pathinfo function in PHP returns information about the path of a file or directory in the form of an associative array or a string, depending on the option chosen in $option.

pathinfo(string $path, int $options = PATHINFO_DIRNAME | PATHINFO_BASENAME | PATHINFO_EXTENSION | PATHINFO_FILENAME): mixed

Caution
The pathinfo() function takes into account the locale setting (regional config). Therefore, to correctly parse a path that contains multibyte characters, the corresponding locale setting must be set using the setlocale() function.

Parameters

$path – the path to be analyzed.

$options – You have these constants as possible parameters:

• PATHINFO_DIRNAME,
• PATHINFO_BASENAME,
• PATHINFO_EXTENSION
• PATHINFO_FILENAME
• PATHINFO_ALL

Returns

If $options is not specified, the constant PATHINFO_ALL will be used by default. This will return all available elements as an associative array.

If another constant (flag) is used, it will return the specified element(s) as a string.

Examples

Firstly, we need to know what elements are returned inside the associative array, which I couldn’t find on php.net. However, we can find out by running a var_dump on the result.

$path = '/home/user/Documents/archivo.txt';
$info = pathinfo($path);
var_dump($info);

array(4) {
  ["dirname"]=>
  string(20) "/home/user/Documents"
  ["basename"]=>
  string(11) "archivo.txt"
  ["extension"]=>
  string(3) "txt"
  ["filename"]=>
  string(7) "archivo"
}

As you can see, info['basename'] gives the same result as running basename(), and info['dirname'] is equivalent to running dirname().

Remember that we saw that if our path starts with a dot, everything after it is treated as an extension. Let’s see an example of that now.

$path = '/home/user/Documents/.archivo.txt';
$info = pathinfo($path);
var_dump($info);

array(4) {
  ["dirname"]=>
  string(20) "/home/user/Documents"
  ["basename"]=>
  string(12) ".archivo.txt"
  ["extension"]=>
  string(3) "txt"
  ["filename"]=>
  string(8) ".archivo"
}

I’m glad that this has pleasantly surprised you. It seems that in this case, it doesn’t behave exactly as mentioned in the notes on php.net. This could be due to version differences. However, it is true that it removes the last extension.

$partes_ruta = pathinfo('/path/emptyextension.');
var_dump($partes_ruta);

array(4) {
  ["dirname"]=>
  string(5) "/path"
  ["basename"]=>
  string(15) "emptyextension."
  ["extension"]=>
  string(0) ""
  ["filename"]=>
  string(14) "emptyextension"
}

Finally, I will provide an example for the constants that will give us a string as a return. Let’s remember that these constants are as follows:

• PATHINFO_DIRNAME,
• PATHINFO_BASENAME,
• PATHINFO_EXTENSION
• PATHINFO_FILENAME

$partes_ruta = pathinfo('/path/emptyextension/parr.txt',PATHINFO_DIRNAME);
var_dump($partes_ruta);

string(20) "/path/emptyextension"