#!/usr/bin/env python#encoding: utf-8'''思路: /proc/xx_pid/status 文件中的关键字段 VmRSS 来获取某个进程占用的物理内存步骤: 获取 httpd 进程ID列表 --> 通过每个进程id来获取该进程占用物理内存'''from subprocess import Popen, PIPEimport os,sys# 通过程序名称获取 pid 列表def getProgPids(prog):    p = Popen(['pidof', prog], stdout=PIPE, stderr=PIPE)    pids = p.stdout.read().split()    return pids# 通过具体的进程 id 来获取该进程占用的物理内存def getMemByPid(pid):    fn = os.path.join('/proc', pid, 'status')    with open(fn) as fd:        for line in fd:            if line.startswith('VmRSS'):                mem = int(line.split()[1])                break    return mem# 获取 httpd 服务所有进程占用的物理内存def getHttpdMem():    httpd_mem_sum = 0    pids = getProgPids('httpd')    for pid in pids:        httpd_mem_sum += getMemByPid(pid)    return httpd_mem_sum# 获取系统总的物理内存def getOsTotalMemory():        with open('/proc/meminfo') as fd:        for line in fd:            if line.startswith('MemTotal'):                total_mem = int(line.split()[1])                break    return total_memif __name__ == '__main__':    http_mem  =  getHttpdMem()    total_mem =  getOsTotalMemory()    scale = http_mem / float(total_mem) * 100    print 'Httpd: %d KB' % http_mem    print 'Percent: %.2f%%' % scale