def grr_head(line):
"""Reads the first bytes of a specified file.
Args:
line: A string representing arguments passed to the magic command.
Returns:
Specified number of the first bytes of the file.
Raises:
NoClientSelectedError: Client is not selected to perform this operation.
"""
args = grr_head.parser.parse_args(shlex.split(line))
return magics_impl.grr_head_impl(path=args.path,
bytes=args.bytes,
offset=args.offset,
cached=args.cached)
def testNoClientSelected(self):
with self.assertRaises(magics_impl.NoClientSelectedError):
magics_impl.grr_head_impl('foo')