Calculate /proc/*/maps statistics

mapstat.py

#!/usr/bin/env python3

import sys
import os.path

usage =  \
'''
Usage: mapstat PID
'''

def print_usage():
    print(usage)
    sys.exit(-1)

def parse_line(line):
    tokens = list(filter(lambda x: x, line.split(' ')))
    if len(tokens) == 6:
        mem_range = tokens[0]
        mem_start, mem_end = map(lambda x: int('0x'+x, 16), mem_range.split('-'))
        mem_size = mem_end - mem_start
        map_file = tokens[-1].strip()
        return (mem_size, map_file) if (mem_size and map_file) else None
    return None

def human_readable(num):
    if num < 1024:
        return str(num) + 'B'
    elif num < 1024 ** 2:
        return str(int(num / 1024)) + 'KB'
    elif num < 1024 ** 3:
        return str(int(num / 1024**2)) + 'MB'

def main():
    if len(sys.argv) != 2:
        print_usage()

    try:
        pid = int(sys.argv[1])
    except:
        print_usage()

    map_file = '/proc/%d/maps' % pid

    if not os.path.exists(map_file):
        print_usage()

    cache = {}
    with open(map_file) as maps:
        for line in maps:
            result = parse_line(line)
            if result:
                size, map_file = result
                cache[map_file] = cache.get(map_file, 0) + size
    
    sorted_keys = sorted(cache.keys(), key=lambda x: cache[x], reverse=True)
    for map_file in sorted_keys:
        size = human_readable(cache[map_file])
        print(size, '\t', map_file)

if __name__ == '__main__':
    main()