определить тип файла (determine file type)
Окружение (Environment)
The environment variable MAGIC can be used to set the default magic
file name. If that variable is set, then file will not attempt to
open $HOME/.magic. file adds '.mgc' to the value of this variable
as appropriate. The environment variable POSIXLY_CORRECT controls
(on systems that support symbolic links), whether file will attempt
to follow symlinks or not. If set, then file follows symlink,
otherwise it does not. This is also controlled by the -L and -h
options.
