определить тип файла (determine file type)
Стандарты (Conforming to)
This program is believed to exceed the System V Interface
Definition of FILE(CMD), as near as one can determine from the
vague language contained therein. Its behavior is mostly
compatible with the System V program of the same name. This
version knows more magic, however, so it will produce different
(albeit more accurate) output in many cases.
The one significant difference between this version and System V is
that this version treats any white space as a delimiter, so that
spaces in pattern strings must be escaped. For example,
>10 string language impress (imPRESS data)
in an existing magic file would have to be changed to
>10 string language\ impress (imPRESS data)
In addition, in this version, if a pattern string contains a
backslash, it must be escaped. For example
0 string \begindata Andrew Toolkit document
in an existing magic file would have to be changed to
0 string \\begindata Andrew Toolkit document
SunOS releases 3.2 and later from Sun Microsystems include a file
command derived from the System V one, but with some extensions.
This version differs from Sun's only in minor ways. It includes
the extension of the '&' operator, used as, for example,
>16 long&0x7fffffff >0 not stripped
