The os module helps Python talk to the Operating System.

As a red teamer / bug hunter / pentester etc …, you can use os module to:

Work with files and folders
Change current directory
Read environment variables (like PATH)
Build paths in a safe way

In this lesson we do no OOP. Only simple scripts.

1. Import `os`#

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import os

You write this at the top of your script.

2. Current Working Directory (CWD)#

The current working directory is the folder where your script is running. (pwd in linux)

2.1 Get current directory#

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import os
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current = os.getcwd()
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print(current)

Example output:

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/home/zeroshadow/tools

This is useful to know where you are before reading or writing files.

2.2 Change directory (cd in Linux)#

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import os
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os.chdir("/home/zeroshadow/Documents")
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print(os.getcwd())

Example output:

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/home/zeroshadow/Documents

As a red teamer, you can change into:

loot folders
reports folders
wordlists folders

3. List Files and Folders (ls in linux)#

3.1 `os.listdir()`#

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import os
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items = os.listdir(".")  # "." means current directory
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print(items)

Example output:

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['wordlists', 'reports', 'scan.py']

This is useful to:

See if wordlist exists
See scan result files
Check for log files

3.2 List files in a specific path#

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import os
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items = os.listdir("/home/zeroshadow/recon")
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print(items)

4. Create and Remove Folders#

4.1 Create one folder — `os.mkdir()`#

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import os
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os.mkdir("loot")
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print("Folder created: loot")

Now a folder named loot exists.

4.2 Create many nested folders — `os.makedirs()`#

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import os
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os.makedirs("loot/targets/reports")
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print("Folders created: loot/targets/reports")

4.3 Remove empty folder — `os.rmdir()`#

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import os
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os.rmdir("empty_folder")
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print("Removed: empty_folder")

⚠ os.rmdir() works only if folder is empty.

5. Work with Files#

For red team, files are:

scan.txt
targets.txt
passwords.txt

5.1 Delete a file — `os.remove()`#

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import os
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os.remove("old_scan.txt")
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print("Deleted old_scan.txt")

5.2 Rename a file — `os.rename()`#

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import os
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os.rename("scan_temp.txt", "scan_final.txt")
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print("Renamed file")

5.3 Rename / move a file to folder#

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import os
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os.rename("scan_final.txt", "reports/scan_final.txt")
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print("Moved scan_final.txt to reports/")

This is useful after a scan: move result file into a reports folder.

6. Paths — `os.path`#

You should not hard-code paths with / or \\. Windows and Linux are different.

Use os.path to build paths in a safe way.

6.1 Join paths — `os.path.join()`#

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import os
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base = "/home/zeroshadow/recon"
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file_name = "targets.txt"
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path = os.path.join(base, file_name)
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print(path)

Example output (Linux):

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/home/zeroshadow/recon/targets.txt

6.2 Check if path exists — `os.path.exists()`#

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import os
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if os.path.exists("wordlists/common.txt"):
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    print("Wordlist found!")
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else:
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    print("Wordlist missing!")

Example output:

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Wordlist found!

6.3 Check if it is a file or folder#

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import os
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path = "reports"
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if os.path.isdir(path):
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    print(path, "is a directory")
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if os.path.isfile("scan.txt"):
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    print("scan.txt is a file")

Example output:

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reports is a directory
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scan.txt is a file

7. Environment Variables — `os.environ`#

Environment variables store system data like:

PATH
HOME
API keys (sometimes)

7.1 Read all environment variables#

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import os
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env = os.environ
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print(env)

Output is big. It shows many keys and values.

7.2 Read one variable (example: `PATH`)#

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import os
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path = os.environ.get("PATH")
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print("PATH:")
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print(path)

As a red teamer, you can:

See where binaries are
See if a tool folder is in PATH

7.3 Set environment variable (only in this script)#

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import os
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os.environ["API_KEY"] = "test123"
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print(os.environ.get("API_KEY"))

Output:

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test123

This is useful for tools that read API keys from environment.

8. Walk Through Directories — `os.walk()`#

os.walk() lets you go through folders and files inside. Very useful for:

Finding config files
Looking for .php, .log, .bak, .zip, etc.

8.1 Simple walk example#

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import os
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for root, dirs, files in os.walk("."):
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    print("Current folder:", root)
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    print("Subfolders:", dirs)
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    print("Files:", files)
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    print("----")

This prints all folders and files under current directory.

8.2 Find all `.log` files#

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import os
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for root, dirs, files in os.walk("."):
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    for f in files:
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        if f.endswith(".log"):
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            full_path = os.path.join(root, f)
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            print(full_path)

As a red teamer, you can search for:

.log (logs)
.bak (backup files)
.sql (database dumps)
.conf (config files)

9. Running System Commands (Basic)#

For real work, it is better to use subprocess, but here is a simple example with os.system().

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import os
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os.system("ls")  # on Linux

Or on Windows:

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import os
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os.system("dir")

This runs the command in the shell. For red team, you can:

Call nmap
Call ping
Call your own tools

⚠ For serious tools, use subprocess instead. It is safer.

10. Mini Red-Team Examples#

10.1 Check Important Folders#

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import os
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paths = ["wordlists", "reports", "loot"]
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for p in paths:
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    if os.path.exists(p):
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        print(p, "OK")
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    else:
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        print(p, "MISSING")

Example output:

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wordlists OK
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reports MISSING
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loot OK

10.2 List Only `.txt` Files in Current Folder#

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import os
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for name in os.listdir("."):
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    if name.endswith(".txt"):
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        print("TXT:", name)

Example output:

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TXT: targets.txt
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TXT: passwords.txt
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TXT: scan.txt

⭐ Final Project — Simple Red Team File Manager#

Goal: build a small script that:

Creates folders for a target
Saves paths in a clean way
Checks if important files exist
Lists report files

🔹 Step 1 — Code#

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import os
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# 1) Ask for target name
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target = input("Enter target name (example: acme.com): ").strip()
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# 2) Build base folder for this target
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base_dir = os.path.join("loot", target)
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reports_dir = os.path.join(base_dir, "reports")
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wordlists_dir = os.path.join(base_dir, "wordlists")
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# 3) Create folders if they do not exist
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for folder in [base_dir, reports_dir, wordlists_dir]:
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    if not os.path.exists(folder):
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        os.makedirs(folder)
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        print("Created:", folder)
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    else:
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        print("Exists:", folder)
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# 4) Check for a main wordlist file inside wordlists
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main_wordlist = os.path.join(wordlists_dir, "main.txt")
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if os.path.exists(main_wordlist):
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    print("Wordlist found:", main_wordlist)
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else:
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    print("Wordlist missing:", main_wordlist)
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# 5) List report files if any
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print("\nReport files:")
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if os.path.exists(reports_dir):
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    files = os.listdir(reports_dir)
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    if not files:
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        print("No reports yet.")
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    else:
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        for f in files:
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            print("-", f)
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else:
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    print("Reports folder does not exist.")

🔹 Step 2 — What this project does#

Asks you for a target name (like acme.com)
Creates this structure if missing:
- loot/<target>/
- loot/<target>/reports/
- loot/<target>/wordlists/
Checks if loot/<target>/wordlists/main.txt exists
Lists report files in loot/<target>/reports/

This is a real base for a red team / bug bounty file system. You can later add:

scan results
screenshots
notes
export to report

End of `os` Module Lesson ✅#

You now know how to:

Work with folders
Work with files
Build paths
Use environment variables
Walk directories

1. Import os#

2. Current Working Directory (CWD)#

2.1 Get current directory#

2.2 Change directory (cd in Linux)#

3. List Files and Folders (ls in linux)#

3.1 os.listdir()#

3.2 List files in a specific path#

4. Create and Remove Folders#

4.1 Create one folder — os.mkdir()#

4.2 Create many nested folders — os.makedirs()#

4.3 Remove empty folder — os.rmdir()#

5. Work with Files#

5.1 Delete a file — os.remove()#

5.2 Rename a file — os.rename()#

5.3 Rename / move a file to folder#

6. Paths — os.path#

6.1 Join paths — os.path.join()#

6.2 Check if path exists — os.path.exists()#

6.3 Check if it is a file or folder#

7. Environment Variables — os.environ#

7.1 Read all environment variables#

7.2 Read one variable (example: PATH)#

7.3 Set environment variable (only in this script)#

8. Walk Through Directories — os.walk()#

8.1 Simple walk example#

8.2 Find all .log files#

9. Running System Commands (Basic)#

10. Mini Red-Team Examples#

10.1 Check Important Folders#

10.2 List Only .txt Files in Current Folder#

⭐ Final Project — Simple Red Team File Manager#

🔹 Step 1 — Code#

🔹 Step 2 — What this project does#

End of os Module Lesson ✅#

1. Import `os`#

3.1 `os.listdir()`#

4.1 Create one folder — `os.mkdir()`#

4.2 Create many nested folders — `os.makedirs()`#

4.3 Remove empty folder — `os.rmdir()`#

5.1 Delete a file — `os.remove()`#

5.2 Rename a file — `os.rename()`#

6. Paths — `os.path`#

6.1 Join paths — `os.path.join()`#

6.2 Check if path exists — `os.path.exists()`#

7. Environment Variables — `os.environ`#

7.2 Read one variable (example: `PATH`)#

8. Walk Through Directories — `os.walk()`#

8.2 Find all `.log` files#

10.2 List Only `.txt` Files in Current Folder#

End of `os` Module Lesson ✅#