Question

Instructions

In this exercise, you will use Python to complete four practical challenges:

• Creating 24 directories for each week of class, each containing 3 folders for each day of class
• Copying files from ~/Downloads into the current directory
• Adding the copy script to the PATH
• Add an alias for the copy script to ~/.bashrc

Class Notes Folder

Create a script called create_notes_drs.py. In the file, define and call a function called main that does the following:

• Creates a directory called CyberSecurity-Notes in the current working directory
• Within the CyberSecurity-Notes directory, creates 24 sub-directories (sub-folders), called Week 1, Week 2, Week 3, and so on until up through Week 24
• Within each week directory, create 3 sub-directories, called Day 1, Day 2, and Day 3

Bonus Challenge: Add a conditional statement to abort the script if the directory CyberSecurity-Notes already exists.

Copying Student Exercises

So far you've used a few different Python modules, but for the rest of the homework, you will need to familiarize yourself with a new one. The shutil module is a Python module used for high-level file operations like moving and copying. Read this beforehand to get familiar with shutil and make sure to use the documentation while you're working through the homework.

Create a script called copy_activities.py with a function called stu_activities that does the following:

• Finds files in ~/Downloads that contain the string Stu_
• Copies these files into the current working directory

Note: This isn't just a challenge to complete for the sake of it, this is a practical script you can run to move any downloaded files from class into your class notes directories.

Copy Class Slides

Create a script called copy_slides.py with a function called pptx_copy Students will create a script that does the following:

• Finds files in ~/Downloads with the file extension .pptx or .ppt
• Copies these files into the current working directory

Note: This is another practical script you can use to move downloaded slides from class into your class notes directories.

Updating PATH and Add an Alias

Note: Consider this a bonus. You do not need to complete this step for credit. But, these tools will come up in class later, so you're strongly encouraged to study up now!

Now these great scripts have been written, but they are only executable from their relative path - where the files are in your system. In this final step, we'll make them accessible to you anywhere in your system directory.

• First, read the following article to learn more about .bashrc, PATH, aliases, and the export command and answer the following questions.
  • What is the main difference betweeen ~/.bashrc and the ~/.bash_profile?
  • What does the export PATH command do?
  • What is the benefit of creating aliases?
• Create a directory called /usr/local/bin and move your three scripts into this directory.
• Update your .bashrc to add the directory /usr/local/bin to PATH with the following command:

export PATH=$PATH:/usr/local/bin

• Finally create aliases in .bashrc for the three scripts
  • alias copy_activities="copy_activities.py"
  • alias copy_slides="copy_slides.py"
  • alias create_notes_drs="create_notes_drs.py"

Answer 1

What is the main difference betweeen ~/.bashrc and the ~/.bash_profile?
.bash_profile is executed for login shells, while .bashrc is executed for interactive non-login shells.

What does the export PATH command do?
Export command marks an environment variable to be exported with any newly forked child processes and
thus it allows a child process to inherit all marked variables.

What is the benefit of creating aliases?
• It eliminates the need to manage multiple email addresses for a single website.
• With it, you don’t need to create new email addresses.

Add scripts to bash file.

• alias copy_activities="copy_activities.py"
• alias copy_slides="copy_slides.py"
• alias create_notes_drs="create_notes_drs.py"

create_notes_drs.py

import os, errno

def createDirectory(path, k=24):
    week = "Week"
    for w in range(1, k+1):
        weekPath = path+"/"+week+" "+str(w)
        os.makedirs(weekPath, exist_ok=True)
        for d in range(1, 4):
            day = "Day"
            os.makedirs(weekPath+"/"+day+" "+str(d), exist_ok=True)

def main():
    directory = "CyberSecurity-Notes"
    dir = os.path.exists(directory)
    if not dir:
        try:
            os.makedirs(directory)
            createDirectory(directory)
        except OSError as e:
            if e.errno != errno.EEXIST:
                raise Exception("unable to create dir")
    else:
        raise Exception("Directory already exist!")
main()

copy_activities.py

import os, fnmatch
import shutil

def stu_activities():
    downloadsPath = os.path.os.path.expanduser("~")+"/Downloads/"
    ls = fnmatch.filter(os.listdir(downloadsPath), 'Stu_*')
    for i in ls:
        shutil.copyfile(downloadsPath+"/"+i, "./"+i)  
stu_activities()

copy_slides.py

import os, fnmatch
import shutil

def pptx_copy():
    downloadsPath = os.path.os.path.expanduser("~")+"/Downloads/"
    lsPDF = fnmatch.filter(os.listdir(downloadsPath), '*.pptx')
    lsPEM = fnmatch.filter(os.listdir(downloadsPath), '*.ppt')
    totalFiles = lsPDF+lsPEM
    for i in totalFiles:
        shutil.copyfile(downloadsPath+"/"+i, "./"+i)
    return   
pptx_copy()