#!/usr/bin/env python3
import os
from subprocess import call
from sys import argv, stderr, stdin, stdout, version_info

def parpid(pid):
    pid=str(pid)
    if not int(pid):
        return None
    fn='/proc/'+pid+'/status'
    with open(fn) as s:
        for line in s:
            a,b = line.split()[:2]
            if a=='PPid:':
                return b

def dopids(pid):
    pid=str(pid)
    pids=[pid]
    while pid:
        pid=int(pid)
        pid=parpid(pid)
        if not int(pid):
            return pids
        pids.append(str(pid))

def main(args):
    s=None
    this=os.getpid()
    if len(args)>1:
        for arg in argv[1:]:
            s=dopids(arg)
    else:
        s=dopids(os.getpid())
#    print(' '.join(s))
    cmd=['ps']
    for p in s:
        call(cmd+[p])
        cmd[1:2]=['h']
    return 0

if __name__ == '__main__':
    if version_info.major < 3:
        BrokenPipeError = IOError
    try:
        result=main(argv)
        stdout.flush()
    except BrokenPipeError:
        result = 99
    except KeyboardInterrupt:
        print('')
        result = 98
    if result is 0 or result is None or result is True:
        exit(0)
    if result is 1 or result is False:
        exit(1)
    if isinstance(result,str):
        print(result,file=stderr)
        exit(2)
    try:
        exit(int(result))
    except ValueError:
        print(str(result),file=stderr)
        exit(3)
    except TypeError:
        exit(4)
# EOF