Resolving Firmlinks in Python

resolve-firmlinks.py

import fcntl
import os

path = '/Applications/Safari.app/'

# MacOS-only fcntl command defined in xnu/bsd/sys/fcntl.h
F_GETPATH_NOFIRMLINK = 102

# The documented max length of an fcntl buffer in python documentation.
FCNTL_MAX_LENGTH = 1024

fd = os.open(path, os.O_DIRECTORY)
full_path_bytes = fcntl.fcntl(fd, F_GETPATH_NOFIRMLINK, bytes(FCNTL_MAX_LENGTH))
full_path = full_path_bytes.decode('utf-8')