#shell command

PIPE, stderr=subprocess.

Basic SHELL commands (for Putty)

Overview of the most common basic SHELL commands. I typically use PuTTY, a free telnet and SSH Client for Windows and Unix platforms. It is lightweight and easy to use and doesn’t need installing (can run from a flash disk).

Navigating directories

cd

…change directory, method used for moving from one folder to another.

cd foldername/foldername2

…would take you to foldername2.

cd…

Ever wondered how to run a linux command like say, grep from within python code? It's fairly simple. Consider I have file1.txt with the following lines:

Hello1 World1 Hello2 World2

Now let's say I have to move all the lines from file1.txt that starts with Hello, to file2.txt

Here's the grep command that'll do it:

grep "^Hello" file1.txt > file2.txt

Okay, now how do I execute this inside a python code? Using subprocess:

import subprocess p = subprocess.Popen('grep "^Hello" file1.txt > file2.txt', stdout=subprocess.PIPE,shell=True) p.communicate()

If you don't want to redirect to file2.txt, but rather you want to parse the output of the command within python, then you can do this:

import subprocess p = subprocess.Popen('grep "^Hello" file1.txt', stdout=subprocess.PIPE,shell=True) output, errormsg = p.communicate() #do something with output print output

Also do note that as the docs say: