pargs

#!/usr/bin/env python
from __future__ import print_function

def pargs(pdir):
    with open(pdir+'/cmdline') as f:
        cmdline = f.read()
    args = cmdline.split('\0')
    assert(args[-1] == '')      # Terminating NUL
    for i, arg in enumerate(args[:-1]):
        print('argv[%d]: %r' % (i, arg))

def penv(pdir):
    with open(pdir+'/environ') as f:
        environ = f.read()
    env = environ.split('\0')
    assert(env[-1] == '')      # Terminating NUL
    for ev in env[:-1]:
        print(ev)

def pstack(pdir):
    # with open(pdir+'/stack') as f:
    #     print f.read()
    taskdir = os.path.join(pdir, 'task')
    for task in os.listdir(taskdir):
        print('%s:' % task)
        stack = os.path.join(taskdir, task, 'stack')
        try:
            with open(stack) as f:
                print(f.read(), end='')
        except Exception as e:
            print(str(e))

if __name__=='__main__':
    import sys
    import os
    import argparse
    ap = argparse.ArgumentParser()
    ap.add_argument('pid', type=int,
                    help='Process identifier')
    args = ap.parse_args()
    myname = ap.prog
    pdir = '/proc/%d' % args.pid
    if not os.path.isdir(pdir):
        print('%s: Unknown pid %d' % (ap.prog, args.pid),
              file=sys.stderr)
        sys.exit(1)
    if myname == 'pargs':
        pargs(pdir)
    elif myname == 'penv':
        penv(pdir)
    elif myname == 'pstack':
        pstack(pdir)
    else:
        ap.error('Invoked as unknown program')