python编程实例-统计apache进程占用的物理内存

#!/usr/bin/env python

import os
from subprocess import PIPE,Popen

def getPids():
        p = Popen(['pidof','httpd'],stdout=PIPE,stderr=PIPE)
        pids = p.stdout.read().split()
        return pids

def parsePidFile(pids):
        http_sum = 0
        for i in pids:
                fn = os.path.join('/proc/',i,'status')
                with open(fn) as fd:
                        for line in fd:
                                if line.startswith('VmRSS'):
                                        http_mem = int(line.split()[1])
                                        http_sum += http_mem
                                        break
        return http_sum

def total_mem(f):
        with open(f) as fd:
                for line in fd:
                        if line.startswith('MemTotal'):
                                total_sum = int(line.split()[1])
                                return total_sum

if __name__ == '__main__':
        pids = getPids()
        http_sum = parsePidFile(pids)
        total_sum = total_mem('/proc/meminfo')
        print "Apache memory is %s KB" % http_sum
        print "total memory is %s KB" % total_sum
        print "Percent : %.2f %%" % (http_sum/float(total_sum)*100)