$cmd
$cmd :
Guesses the mime type with the binary "file" (only available on *nix).
__construct(string $cmd = 'file -b --mime %s 2>/dev/null')
The $cmd pattern must contain a "%s" string that will be replaced with the file name to guess.
The command output must start with the mime type of the file.
| string | $cmd | The command to run to get the mime type of a file |