end of day 5 week 1

progress.md

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+# Week 1 Progress Map — Updated to Day 4
+
+## Student Profile
+
+* Experience: Fullstack Web Developer (JavaScript, PHP, SQL, HTML, CSS, Python)
+* Goals: System administration (Windows, Linux, macOS), hacking, algorithms, low-level programming
+* Languages: C, Powershell, C#, Bash, SQL, C++, Python
+* Current Focus: CompTIA A+ → CCNA → Security+
+
+---
+
+## Week 1 Overview
+
+* **Concept:** Variables, Conditionals, Loops, Functions, Scope
+* **Goal:** Build foundation in core programming concepts, algorithmic thinking, input validation, and cross-language syntax comparison
+
+### Day 1 — C
+
+* Read user input
+* Count characters in strings
+* Enforce max length
+* Validate first character via ASCII ranges
+* Username validation: letters only, max length, starting letter
+
+### Day 2 — Python
+
+* Conditional logic: Even/Odd number check
+* Count letters in a string
+* Username validation implemented in Python
+* Multiple username validation
+* Runtime analysis (`T(n)` and `T(m, n)`) and time complexity
+
+### Day 3 — SQL (PostgreSQL)
+
+* Filter rows based on string length
+* Select letters-only usernames using regex
+* `CASE WHEN` to classify usernames as Accepted/Refused
+* Aggregate valid usernames count
+* Runtime analysis in SQL (`T(n, m) = n x m`) and scaling discussion
+
+### Day 4 — PowerShell
+
+* Conditional logic: `if / elseif / else`
+* Loops: `foreach` over strings and arrays
+* Input validation: letters only, max 20 characters, starts with letter, no spaces or digits
+* Username validator script for single and multiple usernames
+* Algorithm analysis: runtime `T(n, m) = n x m`, doubling users doubles execution
+* Security perspective: safe and defensive scripting in PowerShell, Windows admin context
+
+---
+
+## Completed Exercises Summary
+
+* **Exercise 1:** Even/Odd number check (Python → PowerShell)
+* **Exercise 2:** Count letters in string
+* **Exercise 3:** Single username validation
+* **Exercise 4:** Multiple usernames validation
+* **Exercise 5:** Algorithm scaling explanation
+
+---
+
+## Next Objectives (Week 1 Day 5)
+
+* Learn **Bash scripting** for Linux sysadmin workflows
+* Apply conditionals, loops, and input validation in Linux environment
+* Translate Day 1–4 algorithms into Bash scripts
+* Emphasize security and defensive programming
+
+---
+
+## Recommendations
+
+* Review regex patterns across languages (C, Python, SQL, PowerShell)
+* Practice linear runtime analysis (`T(n, m)`) in each context
+* Keep all scripts secure, avoid unsafe input handling
+* Document differences in syntax and idioms between languages
+
+---
+
+## Notes
+
+* Student has strong programming background; focus can be on **systems, security, and algorithmic thinking**
+* Real-world project orientation encouraged (username validation → real-world user input handling, audits, or security scripts)
+* Progress map will continue tracking daily exercises, language-specific skills, and algorithmic awareness

week 1/day 5/day5.md

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+
+if the number of user dobules
+
+the time of execution will be multiply by 2
+
+
+$$
+T(n, m) = n \times m
+T(2n, m) = 2 \times n \times m
+Big-O: O(n·m)
+$$

week 1/day 5/exo1.sh

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+#!/bin/bash
+
+read -p "please enter a number : " number
+
+if [[ -z $number ]]; then
+    echo "you must enter a number"
+    exit
+fi
+
+if (( $number % 2 == 0 )); then
+    echo "Even"
+else
+    echo "Odd"
+fi

week 1/day 5/exo2.sh

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+#!/bin/bash
+
+read -p "please enter a phrase: " text
+
+if [[ -z "$text" ]]; then
+    echo "please enter a string"
+    exit
+fi
+
+count=0
+
+for ((i=0; i<${#text}; i++)); do
+    char="${text:i:1}"
+    if [[ "$char" =~ [A-Za-z]]]; then
+        count++
+    fi
+done
+
+echo "Your string contain $count letter"

week 1/day 5/exo3.sh

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+#!/bin/bash
+
+read -p "Please enter your username: " username
+
+if [[ -z "$username" ]]; then
+    echo "You must enter a username"
+    exit 1
+fi
+
+badChar=false
+
+for ((i=0; i<${#username}; i++)); do
+    char="${username:i:1}"
+    if ! [[ "$char" =~ [A-Za-z] ]]; then
+        badChar=true
+        break
+    fi
+done
+
+firstChar="${username:0:1}"
+validFirstLetter=false
+
+if [[ "$firstChar" =~ [A-Za-z] ]]; then
+    validFirstLetter=true
+fi
+
+if ! $badChar && (( ${#username} <= 20 )) && $validFirstLetter; then
+    echo "The username $username is valid"
+else
+    echo "The username is not valid"
+fi

week 1/day 5/exo4.sh

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+#!/bin/bash
+
+users=("admin" "root1" "John_Doe" "Alice" "Bob42")
+
+badChar=false
+
+for username in "${users[@]}"; do
+
+    badChar=false
+
+    for ((i=0; i<${#username}; i++)); do
+        char="${username:i:1}"
+        if ! [[ "$char" =~ [A-Za-z] ]]; then
+            badChar=true
+            break
+        fi
+    done
+
+    firstChar="${username:0:1}"
+    validFirstLetter=false
+
+    if [[ "$firstChar" =~ [A-Za-z] ]]; then
+        validFirstLetter=true
+    fi
+
+    if ! $badChar && (( ${#username} <= 20 )) && $validFirstLetter; then
+        echo "The username $username is valid"
+    else
+        echo "The username $username is not valid"
+    fi
+
+done
+

week 1/day 5/readme.md

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+# 📘 Week 1 · Day 5 — Bash Exercises
+
+This README documents **all exercises for Week 1 Day 5**, focused on **Bash scripting for Linux system administration and security workflows**.
+
+The exercises mirror the logic implemented previously in **C, Python, SQL, and PowerShell**, reinforcing algorithmic thinking while introducing **Unix shell syntax, conditionals, loops, and defensive scripting**.
+
+---
+
+## 🎯 Learning Objectives
+
+By completing today’s exercises, you will:
+
+* Use Bash variables and user input (`read`)
+* Apply conditional logic with `if / elif / else`
+* Loop over strings and arrays using `for`
+* Perform character validation using regex
+* Implement secure input validation logic
+* Analyze algorithm runtime and scalability
+* Gain confidence writing Linux automation scripts
+
+---
+
+## 🛠 Exercises Overview
+
+### 🧪 Exercise 1 — Even / Odd Number Checker
+
+**Task:**
+
+* Prompt the user for a number
+* Determine whether the number is `Even` or `Odd`
+
+**Concepts practiced:**
+
+* Numeric input handling
+* Arithmetic expressions: `(( ))`
+* Conditional branching
+
+---
+
+### 🧪 Exercise 2 — Count Letters in a String
+
+**Task:**
+
+* Prompt the user for a string
+* Count **letters only** (`A–Z`, `a–z`)
+* Ignore spaces, digits, and special characters
+
+**Concepts practiced:**
+
+* Looping over string characters
+* Regex matching using `[[ =~ ]]`
+* Counter variables
+
+---
+
+### 🧪 Exercise 3 — Username Validator (Single User)
+
+**Task:**
+Validate a username using these rules:
+
+* Length ≤ 20 characters
+* Starts with a letter
+* Contains letters only
+* No digits
+* No spaces
+
+**Output:**
+
+* `Accepted` or `Refused`
+
+**Concepts practiced:**
+
+* Defensive input validation
+* Early exit with `break`
+* String length checking
+* First-character validation
+
+---
+
+### 🧪 Exercise 4 — Validate Multiple Usernames
+
+**Input:**
+
+```bash
+users=("admin" "root1" "John_Doe" "Alice" "Bob42")
+```
+
+**Task:**
+
+* Loop through each username
+* Apply the same validation rules as Exercise 3
+* Print whether each username is valid or invalid
+
+**Concepts practiced:**
+
+* Array iteration
+* Nested loops
+* Reusable validation logic
+
+---
+
+### 🧪 Exercise 5 — Algorithm Analysis (Written)
+
+**Task:**
+Explain what happens to execution time if the number of usernames doubles.
+
+Use:
+
+* `n` = number of usernames
+* `m` = average username length
+
+**Expected result:**
+
+```
+T(n, m) = n × m
+T(2n, m) = 2 × n × m
+Big-O: O(n·m)
+```
+
+---
+
+## 🔐 Security & Sysadmin Perspective
+
+These exercises reflect real-world Bash usage in:
+
+* Linux user management
+* Input validation scripts
+* SSH and access control automation
+* Log parsing and monitoring
+* Security audits and recon scripts
+
+Strong validation and predictable runtime are critical for **secure and reliable system scripts**.
+
+---
+
+## ✅ Completion Criteria
+
+Day 5 is complete when:
+
+* Exercises 1–4 run correctly in Bash
+* Exercise 5 clearly explains runtime scaling
+* Scripts follow safe Bash practices (`[[ ]]`, quoting, defensive checks)
+
+---
+
+## 🔜 Next Step
+
+After Day 5, Week 1 concludes.
+
+Upcoming:
+
+* **Week 2:** Data Structures (arrays, maps, sets)
+* Stronger algorithm focus
+* More security-oriented scripting examples
+
+---
+
+📌 *This README serves as a reference and checklist for Week 1 Day 5 Bash exercises.*

week 1/projects/readme.md

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+# 🛠 Bonus Sysadmin Projects — Bash & PowerShell Fundamentals
+
+This README documents a set of **bonus sysadmin-oriented projects** designed to be completed **after Week 1 and before Week 2**.
+
+These projects are practical, security-focused, and closely aligned with **real Linux/Windows system administration, automation, and security analysis tasks**. They reinforce core programming concepts (loops, conditionals, validation, algorithms) in both **Bash (Linux)** and **PowerShell (Windows)** environments.
+
+---
+
+## 🎯 Purpose of These Projects
+
+These bonus projects exist to:
+
+* Bridge theory → real-world sysadmin work
+* Strengthen Bash and PowerShell scripting confidence
+* Apply algorithmic thinking to system tasks
+* Build habits required for **A+ → CCNA → Security+** paths
+* Prepare for Week 2 (Data Structures & Algorithms)
+
+They simulate tasks performed by:
+
+* Linux and Windows system administrators
+* Security analysts / SOC engineers
+* DevOps and cloud engineers
+* Blue team / hardening roles
+
+---
+
+## 🧰 Project 1 — User Audit Script
+
+### Goal
+
+Audit local users and identify potentially unsafe usernames.
+
+### Tasks
+
+* Read usernames from `/etc/passwd` (Linux) or `Get-LocalUser` (PowerShell)
+* Extract the username field
+* Validate usernames using rules:
+
+  * Letters only
+  * Length ≤ 20
+  * Starts with a letter
+* Print only invalid usernames
+
+### Skills Reinforced
+
+* File reading / system commands
+* Field parsing
+* Loops and validation logic
+* Defensive system auditing
+
+---
+
+## 🔐 Project 2 — Password Policy Checker (Simulation)
+
+> ⚠️ No real passwords — this is a simulation exercise
+
+### Goal
+
+Validate whether a password string meets a security policy.
+
+### Tasks
+
+* Prompt user for a password
+* Enforce rules such as:
+
+  * Minimum length (e.g., ≥ 12)
+  * At least one letter
+  * At least one digit
+  * At least one special character
+* Output `Strong` or `Weak`
+
+### Skills Reinforced
+
+* Multiple counters / flags
+* Regex checks
+* Early exit logic
+* Secure input validation
+
+---
+
+## 📄 Project 3 — Log File Scanner
+
+### Goal
+
+Scan a log file for suspicious activity indicators.
+
+### Tasks
+
+* Read a log file line by line
+* Detect keywords such as:
+
+  * `failed`
+  * `error`
+  * `unauthorized`
+* Count occurrences of each keyword
+* Print a summary report
+
+### Skills Reinforced
+
+* File iteration
+* Pattern matching
+* Counters
+* Incident response fundamentals
+
+---
+
+## 🖥 Project 4 — Service Status Monitor
+
+### Goal
+
+Verify whether critical system services are running.
+
+### Tasks
+
+* Define an array/list of services (e.g., `ssh`, `cron`, `ufw` in Linux; `WinRM`, `wuauserv` in Windows)
+* For each service:
+
+  * Check if it is running
+  * Print `OK` or `NOT RUNNING`
+
+### Skills Reinforced
+
+* Arrays / collections
+* Command execution and exit code checking
+* Automation patterns in Bash and PowerShell
+
+---
+
+## 📊 Project 5 — Algorithm Reflection (Written)
+
+### Goal
+
+Build the habit of analyzing performance in real scripts.
+
+### Tasks
+
+For **one of the projects above**, answer:
+
+* What is `n` in this script?
+* What is the time complexity?
+* What happens if the input doubles?
+
+### Example
+
+```
+T(n) = n
+T(2n) = 2n
+Big-O: O(n)
+```
+
+---
+
+## ✅ Completion Guidelines
+
+* These projects are **optional but strongly recommended**
+* Completing **2–3 projects** is sufficient before Week 2
+* Focus on:
+
+  * Correctness
+  * Readability
+  * Defensive coding
+  * Clear logic
+* Implement each project in **both Bash and PowerShell** if possible for dual practice
+
+---
+
+## 🔜 What Comes Next
+
+After completing the bonus projects:
+
+* Proceed to **Week 2 — Data Structures & Early Algorithms**
+* Arrays, maps, sets
+* Searching algorithms
+* Clear math explanations with real system examples
+
+---
+
+📌 *These bonus sysadmin projects are designed to turn programming fundamentals into practical Linux and Windows administration and security skills.*