#!/usr/bin/python
import time

FNAME='/proc/stat'

def readBody():
    fp = open(FNAME, 'r')
    lines = []
    try:
        lines.extend([l.strip() for l in fp])
    finally:
        fp.close()
    return lines

def splitBody():
    lines = []
    lines.extend(l.split() for l in readBody())
    return lines


class CPUTime:
    user = 0
    nice = 0
    system = 0
    idle = 0
    total = 0

    def parse(self, line):
        self.user = long(line[1])
        self.nice = long(line[2])
        self.system = long(line[3])
        self.idle = long(line[4])
        self.total = float(self.user + self.nice + self.system + self.idle)

    def __repr__(self):
        return 'user=%s, nice=%s, sys=%s, idle=%s, total=%s' % (self.user, self.nice, self.system, self.idle, self.total)

    def usageUser(self):
        return self._doPercentage(self.user)

    def usageNice(self):
        return self._doPercentage(self.nice)

    def usageSystem(self):
        return self._doPercentage(self.system)

    def usageIdle(self):
        return self._doPercentage(self.idle)

    def delta(self, other):
        self.user -= other.user
        self.nice -= other.nice
        self.system -= other.system
        self.idle -= other.idle
        self.total -= other.total

    def copy(self):
        t = CPUTime()
        t.user = self.user
        t.nice = self.nice
        t.system = self.system
        t.idle = self.idle
        t.total = self.total
        return t

    def _doPercentage(self, a):
        return a / self.total * 100.0;

def main():
    print 'Collecting first sample'

    first = CPUTime()
    first.parse(splitBody()[0])


    while True:
        time.sleep(1)
        second = CPUTime()
        second.parse(splitBody()[0])
        secondCopy = second.copy()
        second.delta(first)
        print 'user=%s, nice=%s, sys=%s, idle=%s' % (second.usageUser(), second.usageNice(), second.usageSystem(), second.usageIdle())
        first = secondCopy
        
    

if __name__ == '__main__':
    main()