[Python] 利用commands模块执行Linux shell命令

用Python写运维脚本时,经常需要执行linux shell的命令,Python中的commands模块专门用于调用Linux shell命令,并返回状态和结果,下面是commands模块的3个主要函数:

1. commands.getoutput('shell command')

执行shell命令,返回结果(string类型)

>>> commands.getoutput('pwd')
'/home/oracle'

 

2. commands.getstatus('file')

该函数已被python丢弃,不建议使用,它返回 ls -ld file 的结果(String)(返回结果太奇怪了,难怪被丢弃)

>>> commands.getstatus('admin.tar')
'-rw-rw-r-- 1 oracle oracle 829440 Jan 29 10:36 admin.tar'


3. commands.getstatusoutput('shell command')

执行shell命令, 返回两个元素的元组tuple(status, result),status为int类型,result为string类型。

cmd的执行方式是{ cmd ; } 2>&1, 故返回结果包含标准输出和标准错误. 

>>> commands.getstatusoutput('pwd')
(0, '/home/oracle')


下面的一个脚本利用commands模块检测磁盘使用率,标识出大于10%的磁盘(百分比可根据实际情况调整,一般设为90%,本例为了更好的说明情况,设为10%):

import commands

threshold = 10
flag = False

title=commands.getoutput("df -h|head -1")

'''
Check sda disk space usage like below format:
/dev/sda2              20G  2.3G   17G  13% /
/dev/sda6              20G  306M   19G   2% /var
/dev/sda3              49G  2.8G   44G   7% /home
/dev/sda5              49G  4.5G   42G  10% /opt
/dev/sda1             194M   12M  172M   7% /boot
'''

chkDiskList=commands.getoutput("df -h|grep sda").split('\n')
usedPercents=commands.getoutput("df -h|grep sda|awk '{print $5}'|grep -Eo '[0-9]+'").split('\n')

for i in range(0,len(usedPercents)):
  if int(usedPercents[i]) >= threshold:
    chkDiskList[i] += '    ----Caution!!! space usage >= ' + str(threshold)
    flag = True

'''
Check disk space usage like below format:
/dev/mapper/backup-backup_lv
                      751G   14G  699G   2% /backup
/dev/mapper/data-data_lv
                      751G  172G  540G  25% /data
'''      

        
chkDiskList_2=commands.getoutput("df -h|grep -v sda|grep -v tmp|grep -v system").split('\n')
usedPercents_2=commands.getoutput("df -h|grep -v map|grep -v sda|grep -v tmp|grep -v system|awk '{print $4}'|grep -Eo '[0-9]+'").split('\n')

for i in range(0,len(usedPercents_2)): 
  if int(usedPercents_2[i]) >= threshold:
    chkDiskList_2[i*2 + 1] += '    ----Caution!!! space usage >= ' + str(threshold)
    flag = True

if flag == True:
  #combine tile, chkDiskList, chkDisklist_2
  result = [title,]
  result.extend(chkDiskList)
  result.extend(chkDiskList_2)
  for line in result:
    print line


假设当前的磁盘使用率如下:

[oracle@lx200 ~/admin/python]$ df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              20G  2.3G   17G  13% /
/dev/sda6              20G  306M   19G   2% /var
/dev/sda3              49G  2.8G   44G   7% /home
/dev/sda5              49G  4.5G   42G  10% /opt
/dev/sda1             194M   12M  172M   7% /boot
tmpfs                  18G     0   18G   0% /dev/shm
/dev/mapper/backup-backup_lv
                      751G   14G  699G   2% /backup
/dev/mapper/data-data_lv
                      751G  174G  539G  25% /data


执行该脚本后的结果如下:

Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              20G  2.3G   17G  13% /    ----Caution!!! space usage >= 10
/dev/sda6              20G  306M   19G   2% /var
/dev/sda3              49G  2.8G   44G   7% /home
/dev/sda5              49G  4.5G   42G  10% /opt    ----Caution!!! space usage >= 10
/dev/sda1             194M   12M  172M   7% /boot
/dev/mapper/backup-backup_lv
                      751G   14G  699G   2% /backup
/dev/mapper/data-data_lv
                      751G  174G  539G  25% /data    ----Caution!!! space usage >= 10
 
posted @ 2016-08-31 15:28  天涯逐梦  阅读(207)  评论(0编辑  收藏  举报