view process tree in ncdu

psdu

#!/usr/bin/env python3

# Show hierarchical process memory usage via ncdu

# I've updated this to lift children of zsh to make the top level more usefule to me.

import json, subprocess, time, tempfile
from collections import defaultdict
from itertools import dropwhile

def psize(s): return int(s[0:-1])*{'K':2**10, 'M':2**20, 'G':2**30}[s[-1]]
def runcmd(cmd):
    res = subprocess.run(cmd.split(),capture_output=True,text=True)
    return list(dropwhile(lambda x: 'PID' not in x, res.stdout.splitlines()))[1:]

byparent = defaultdict(list)
for line in runcmd("top -l 1 -o mem -stats pid,ppid,mem,command"):
    parts = line.split(maxsplit=3)
    (pid,ppid,sz,cmd) = parts
    pid = int(parts[0])
    ppid = int(parts[1])
    if pid == 0: continue
    sz = psize(parts[2])
    cmd = parts[3].strip()
    byparent[ppid].append((pid,sz,cmd))

# get process name, remove -c for full command line
cmdline = {}
for line in runcmd("ps -ceo pid,command"):
    (pid,cmd) = line.split(maxsplit=1)
    pid = int(pid)
    cmdline[pid] = cmd
    # reparent zsh children to the top
    if cmd.endswith('zsh'):
        byparent[1] += byparent[pid]
        byparent[pid] = []

def mktree(root):
    (pid, sz, name) = root
    name = cmdline.get(pid,name)
    node = {"name": name,"asize":sz,"dsize":sz}
    children = list(map(mktree,byparent[pid]))
    if len(children):
        return [node] + children
    return node

data = [1,2,{"progname": "psdu", "progver": "1.0", "timestamp":int(time.time())}] + list(map(mktree, byparent[0]))
with tempfile.NamedTemporaryFile(mode='w+', suffix='.json', delete=True) as temp:
        json.dump(data, temp)
        temp.flush()
        subprocess.run(['ncdu', '-f', temp.name], check=True)