Python Uptime on Mac for the Masochistic

uptime.py

#!/usr/bin/env python3

import ctypes
import ctypes.util
from datetime import datetime

libc_path = ctypes.util.find_library("libc")

libc = ctypes.cdll.LoadLibrary(libc_path)

USER_SIZE = 256
LINE_SIZE = 32
ID_SIZE = 4
HOST_SIZE = 256
BOOT_TIME = 2


class UTMPX_Entry(ctypes.Structure):
    _fields_ = [
        ("ut_user", ctypes.c_char * USER_SIZE),
        ("ut_id", ctypes.c_char * ID_SIZE),
        ("ut_line", ctypes.c_char * LINE_SIZE),
        ("ut_pid", ctypes.c_int),
        ("ut_type", ctypes.c_short),
        ("ut_tv_secs", ctypes.c_long),
        ("ut_tv_usec", ctypes.c_int),
        ("ut_host", ctypes.c_char * HOST_SIZE),
    ]


getutxent = libc.getutxent
getutxent.restype = ctypes.POINTER(UTMPX_Entry)


def boot_epoch_time():

    while True:
        entry = getutxent()
        if not entry:
            break
        if entry.contents.ut_type == BOOT_TIME:
            return entry.contents.ut_tv_secs
    return 0


if __name__ == "__main__":

    boot_time = datetime.fromtimestamp(boot_epoch_time())
    delta = datetime.now() - boot_time

    print(f"boot @ {boot_time}")
    print(f"delta: {delta}")