Get the Linux birth time of the system or a process using /proc/stat and /proc/pid/stat. For example, you may get local datetime when process 12345 started: import datetime import btime datetime.datetime.fromtimestamp(btime.process_time(12456)[1])

btime.py

'''
Get the Linux birth time of the system or a process using /proc/stat
and /proc/pid/stat.

For example, you may get local datetime when process 12345 started:
import datetime
import btime
datetime.datetime.fromtimestamp(btime.process_time(12456)[1])
'''
import os


def system_btime():
    '''
    Get the timestamp when system is booted.
    '''
    stat = open('/proc/stat').readlines()
    btime_line = [i.strip() for i in stat if i.startswith('btime')]
    return int(btime_line[0].split(' ')[1])

def process_btime(pid):
    '''
    Return a tuple (secs, timestamp) of a process.
    secs is the seconds when process started after system booted,
    timestamp is the seconds.
    '''
    stat = open('/proc/%s/stat' % pid).read()
    clock = int(stat.split(' ')[21])
    secs = clock / os.sysconf('SC_CLK_TCK')
    timestamp = system_btime() + secs
    return secs, timestamp