#!/bin/rc
# top
rfork en

flagfmt='d interval,m maxlines'
args=''

old=/tmp/top.$pid.old
new=/tmp/top.$pid.new
out=/tmp/top.$pid.out

int=2
max=20
len=()

fn usage{
	aux/usage
	exit usage
}
fn isfloat{
	echo $1 | grep -s '^[0-9\.]+$'
}
fn isnum{
	echo $1 | grep -s '^[0-9]+$'
}
fn get{
	grep . */status |
	sed '
		s!/status:! !
		s! +! !g
	'
}
fn clear{
	awk 'END { for(i = 0; i < '$len'; i++) printf "\x08" }' </dev/null
}
fn sigint{
	rm -f $old $new $out
	exit
}
fn top{
	get | tee $new | join - $old |
	awk '
	{
		newusr = $5
		newsys = $6
		oldusr = $17
		oldsys = $18
		delta = newusr + newsys - (oldusr + oldsys)
		pid = $1
		name = $2
		user = $3
		state = $4
		mem = $11
		usr = newusr / 1000
		sys = newsys / 1000
		printf("%-10s %8s %6s %4ld:%.2ld %3ld:%.2ld %8ldK %-8s %s\n",
			user, pid, delta,
			usr / 60, usr % 60,
			sys / 60, sys % 60,
			mem, state, name)
	}
	' |
	sort -nr +2 -3 | sed $max^q
	mv $new $old
}

if(! ifs=() eval `{aux/getflags $*})
	usage
if(~ $#flagd 1){
	if(! isfloat $flagd)
		usage
	int=$flagd
}
if(~ $#flagm 1){
	if(! isnum $flagm)
		usage
	max=$flagm
}
cd /proc
ramfs
get >$old
sleep $int

while(){
	{
		echo
		echo top:
		top
	} >$out
	if(~ $#len 1)
		clear
	len=`{wc -r <$out}
	cat $out
	sleep $int
}