[Python2.x] use the commands module to execute the Linux shell Command, python2.xcommands

[Python2.x] use the commands module to execute the Linux shell Command, python2.xcommands

When writing an O & M script using Python, you often need to execute the linux shell Command. The commands module in Python is used to call the Linux shell Command and return the status and result, the following are the three main functions of the commands module:

1. commands. getoutput ('Shell command ')

Run the shell command to return the result (string type)

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

2. commands. getstatus ('file ')

This function has been discarded by python and is not recommended. It returns the ls-ld file Result (String) (the returned result is so strange that it cannot be discarded)

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

3. commands. getstatusoutput ('Shell command ')

Run the shell command to return the tuple (status, result) of the two elements. status indicates int type, and result indicates string type.

The cmd execution method is {cmd;} 2> & 1. Therefore, the returned results include standard output and standard errors.

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

The following script uses the commands module to detect disk usage and identifies a disk larger than 10% (the percentage can be adjusted according to the actual situation, which is generally set to 90%. In this example, we want to better describe the situation, set to 10% ):

import commandsthreshold = 10flag = Falsetitle=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 = Trueif flag == True:  #combine tile, chkDiskList, chkDisklist_2  result = [title,]  result.extend(chkDiskList)  result.extend(chkDiskList_2)  for line in result:    print line

Assume that the current disk usage is as follows:

[oracle@lx200 ~/admin/python]$ df -hFilesystem            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% /boottmpfs                  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

The result of executing the script is as follows:

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