STEM with Python – Part 9: Command Automation

In the last post of STEM with Python, we learned the very basics of network automation. So, this time, why don’t we learn about Linux command automation? Unlike the last one that experimented with a lot of methods, such as with/without logging the result-output into another file, this time, we’ll see a much simpler coding implementation.

The code:

So, this is the actual code that loops through the specified Linux commands and displays the result in the console. As we learned in the last section, maybe you can also apply the file open/read/write methods to this source code and make it more useful.

command_automation.py

import subprocess

# Define the commands to be run
commands = ["ls -l", "df -h", "uname -a"]

# Iterate through the commands
for command in commands:
    # Run the command and capture the output
    output = subprocess.run(command, shell=True, capture_output=True)

    # Print the output
    print(output.stdout.decode())

The executed result:

$python3 command_automation.py
total 12
-rw-rw-r-- 1 johnito users  383 Jan 14 16:58 cat.py
-rw-rw-r-- 1 johnito users  335 Jan 14 16:52 command_automation.py
-rw-rw-r-- 1 johnito users 1313 Jan 14 16:59 sample.txt

Filesystem                         Size  Used Avail Use% Mounted on
udev                               3.8G     0  3.8G   0% /dev
tmpfs                              787M  6.7M  781M   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv   14G   13G  148M  99% /
tmpfs                              3.9G     0  3.9G   0% /dev/shm
tmpfs                              5.0M     0  5.0M   0% /run/lock
tmpfs                              3.9G     0  3.9G   0% /sys/fs/cgroup
/dev/sdb1                           98G  8.8M   93G   1% /shares/smb/seagate_hdd_100gb
/dev/loop0                          64M   64M     0 100% /snap/core20/1738
/dev/loop1                          64M   64M     0 100% /snap/core20/1778
/dev/loop2                          92M   92M     0 100% /snap/lxd/24061
/dev/sda2                          1.5G  205M  1.2G  15% /boot
/dev/loop3                          92M   92M     0 100% /snap/lxd/23991
/dev/loop4                          50M   50M     0 100% /snap/snapd/17883
/dev/sdc1                          4.6T  184G  4.2T   5% /shares/smb/seagate_hdd_5tb
tmpfs                              787M     0  787M   0% /run/user/1000
/dev/loop5                         117M  117M     0 100% /snap/core/14399
/dev/loop6                         116M  116M     0 100% /snap/kotlin/73
/dev/sdb2                           98G   80K   93G   1% /home/johnito/seagate_hdd_100gb_home
/dev/sdb3                           98G   32K   93G   1% /shares/smb/seagate_hdd_100gb_2
/dev/loop7                          50M   50M     0 100% /snap/snapd/17950
/dev/loop8                         117M  117M     0 100% /snap/core/14447

Linux skynewubuntuserver 5.4.0-135-generic #152-Ubuntu SMP Wed Nov 23 20:19:22 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

Afterthoughts:

Since Python3 is already installed in my environment (Ubuntu Server 20.04), the scripting language’s compatibility with Linux was simply amazing, and the OS-level unified compatibility is something that always makes me implement my ideas into the actual code even easier than other languages when it comes to coding on the Linux platforms.