Monitor CPU-time and max memory usage using ps

sysusg.py

"""
Monitors a process using the `ps` command and records total CPU-time and maximum memory usage.
Example usage:
    ./runMyCommand &
    sysusg.py runMyCommand
"""

import subprocess
import sys
import time

def ps(grep_for):
    proc = subprocess.Popen(["ps", "-A", "-o", "pid,ppid,etime,rss,args"], stdout=subprocess.PIPE)
    (out, err) = proc.communicate()

    second_multipliers = [1, 60, 3600, 86400]
    max_time = 0
    total_rss = 0
    found_command = False

    for line in str(out, 'utf-8').split("\n"):
        if command_contains in line and sys.argv[0] not in line: 
            found_command = True
            tokens = line.split()
            time_tokens = list(map(float, tokens[2].split(":")))
            time_tokens_secs = [t * second_multipliers[len(time_tokens) - 1 - i] for i,t in enumerate(time_tokens)]
            time_s = sum(time_tokens_secs)
            max_time = max(max_time, time_s)
            total_rss += int(tokens[3])

    if found_command:
        return max_time, total_rss
    else:
        return None

command_contains = sys.argv[1]
sample_delay = 0.2  # Unit is seconds

print("Analyzing all processes whose command contains '" + command_contains + "'")
print("Waiting for process(es) to start")
while ps(command_contains) is None:
    time.sleep(sample_delay)

print("Sampling memory and running time every", sample_delay, "seconds until processes finish")
max_rss = 0
max_time = 0

try: 
    while True:
        max_time, rss = ps(command_contains)
        max_rss = max(max_rss, rss)
        time.sleep(sample_delay)
        sys.stdout.write(".")
        sys.stdout.flush()
except TypeError:
    pass

print("")
print("Time:", max_time, "seconds")
print("Memory:", max_rss / 1024.0, "MB")