使用 python 获取 httpd 程序所占用物理内存

#!/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, PIPE
import 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_mem

if __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