procinfo.py

#!/usr/bin/env python
"""Print info in json format about OS process specified by its pid.

   Usage: procinfo PID

   To install:

     $ sudo apt-get install python-psutil # install dependencies
     # https://pypi.python.org/pypi?:action=display&name=psutil#downloads

   Example:

     $ python procinfo.py 3451 | jq .cpu_percent,.memory_percent
     0
     1.848394789177199
"""
import json
import sys
import psutil # $ pip install psutil

try:
    pid = int(sys.argv[1])
except (ValueError, IndexError):
    sys.exit(__doc__) # print usage info and exit

try:
    procinfo = psutil.Process(pid).as_dict()
except (psutil.NoSuchProcess, psutil.AccessDenied):
    sys.exit("can't get process info for %d pid" % pid)
else:
    json.dump(procinfo, sys.stdout, indent=4, sort_keys=True, ensure_ascii=False)