show-mem-usage: parse /proc/{pid}/maps and show how much memory is used by each file/type

show-mem-usage

#!/usr/bin/python3

'''parse /proc/{pid}/smaps and show how much RSS memory is used by each file/type'''

import sys
from collections import defaultdict

def filesize(size: int) -> str:
  units = 'KMGTPEZY'
  left = abs(size)
  unit = -1
  n = len(units)
  while left > 1100 and unit < n:
    left = left / 1024
    unit += 1
  if unit == -1:
    return '%dB' % size
  else:
    if size < 0:
      left = -left
    return '%.1f%siB' % (left, units[unit])

def main():
  data = defaultdict(int)
  maxlen = 0

  for line in sys.stdin:
    first, second, *others, last = line.split(None, 5)
    if len(others) == 3:
      name = last.rstrip()
    elif len(others) == 2:
      name = '[anon]'
    else:
      if first == 'Rss:':
        data[name] += int(second)
        maxlen = max(maxlen, len(name))

  for name, used in sorted(
    data.items(), key=lambda x: x[1]):
    size = filesize(used * 1024)
    size = size[:-3] + ' ' + size[-3:]
    print(f'{name:{maxlen}} {size:>10}')

if __name__ == '__main__':
  main()