Added SED and AWK Sheets.

LEMP.md

@@ -1,272 +0,0 @@
-# Fedora Super-LEMP setup:
-
-*Based on https://www.howtoforge.com/how-to-install-nginx-with-php-and-mariadb-lemp-stack-on-fedora-32/*
-
-## Install packages
-
-### Massive swiss-army knife setup 
-```
-dnf install certbot certbot-nginx cockpit htop iftop iptraf nano openssh-server net-tools nginx* rsync screen vim wget && dnf groupinstall "Development Tools" "Web Server" "Mysql" "php"
-```
-### Or Less Extra
-
-`dnf install certbot certbot-nginx nginx `
-
-`dnf install vim nano rsync screen vim wget net-tools htop iftop iptraf openssh-server bash-completion`
-
-`dnf groupinstall "Development Tools" "Web Server" "Mysql" "php"`
-
-
-### More butter Rocky variant 
- 
-`dnf install epel-release`
-
-`dnf install git vim nano rsync screen vim wget net-tools htop iftop iptraf openssh-server bash-completion mariadb mariadb-server certbot python3-certbot-nginx nginx php-fpm`
-
-`dnf groupinstall "Development Tools"`
-
-## Add non-root administrator
-
-`adduser user`
-
-`usermod -aG wheel user`
-
-`passwd user`
-
-`vi /etc/sudoers`
-
-`sudo -i -u user`
-
-## Configure SSH
-
-`ssh-keygen -t rsa -b 4096`
-
-### Change port and root login settings
-
-`vi /etc/ssh/sshd_config`
-
-### Add keys ( also see `ssh-copy-id` )
-
-`vi .ssh/authorized_keys`
-
-## Firewall settings
-
-```
-systemctl enable firewalld
-systemctl start firewalld
-systemctl stop firewalld
-systemctl restart firewalld
-firewall-cmd --state
-firewall-cmd --set-default-zone=public
-firewall-cmd --zone=public --permanent --list-services
-firewall-cmd --zone=public --permanent --add-service=http
-firewall-cmd --zone=public --permanent --add-service=https
-firewall-cmd --add-port 20022/tcp
-firewall-cmd --permanent --add-port 20022/tcp
-firewall-cmd --permanent --add-port YOUR_PORT_HERE/tcp
-firewall-cmd --remove-service ssh --permanent
-firewall-cmd --reload
-systemctl reload firewalld
-
-```
-
-## MariaDB
-```
-systemctl enable mariadb
-systemctl start mariadb
-mysql_secure_installation # Y-N-Y-Y-Y-Y
-mysql -u root -p
-CREATE USER 'user1'@localhost IDENTIFIED BY 'password1';
-CREATE USER 'namenode'@localhost IDENTIFIED BY ':passwd';
-GRANT ALL PRIVILEGES ON *.* TO 'user1'@localhost IDENTIFIED BY 'password1';
-GRANT ALL PRIVILEGES ON *.* TO 'user2'@localhost IDENTIFIED BY 'passwd2';
-FLUSH PRIVILEGES;
-SHOW GRANTS FOR 'user1'@localhost;
-SHOW GRANTS FOR 'user2'@localhost;
-CREATE DATABASE 'yourDB';
-SHOW DATABASES;
-DROP USER 'user1'@localhost; # Just for example to show how to delete a user
-```
-
-## Redis Setup
-
-`dnf install redis php-redis`
-
-`sudo systemctl enable --now redis`
-
-`vi /etc/redis/redis.conf` 
-
-Change bind (0.0.0.0), `requirepass`, `port (2*)`, `maxmemory` (256mb), and `maxmemory-policy allkeys-lru`.
-
-`systemctl restart redis`
-
-```
-firewall-cmd --zone=public --permanent --add-port=26379/tcp
-firewall-cmd --reload
-```
-
-## NGINX
-
-### Important working directories:
-```
-/usr/share/nginx/
-
-/etc/nginx/
-
-```
-### Create user working directory for custom configuration files:
-```
-mkdir /etc/nginx/sites-available  # Create a directory for nginx.conf files
-
-mkdir /usr/share/nginx/example.com/html -p  # Create new webroot with specified structure
-```
-
-### Now we can create a new config file to start with:
-
-`vi /etc/nginx/sites-available/example.com.conf`
-
-
-### Link it to active conf directory
-
-`ln -s /etc/nginx/sites-available/example.com.conf /etc/nginx/conf.d/`
-
-### If it is required at some point, removing that symlink is as easy as:
-
-`rm /etc/nginx/conf.d/example.com.conf`
-
-
-### Now we edit the nginx.conf
-
-`vi /etc/nginx/nginx.conf`
-
-
-### Set the following lines after the line "include /etc/nginx/conf.d/*.conf" (if not already set):
-```
-server_names_hash_bucket_size 64; # Should already exist in recent versions 
-
-types_hash_max_size 4096; ## Should already be set
-
-``` 
-### Comment out the root location directive (Can uncomment after setup so as not to confuse cache while testing?)
-
-**To test and reload the configuration:**  
-
-`nginx -t`
-`systemctl reload nginx`
-
-### Simple recap moving forward:
-```
-systemctl start nginx
-systemctl restart nginx
-systemctl enable nginx
-systemctl status nginx
-systemctl reload nginx
-nginx -t
-mkdir /etc/nginx/sites-available
-mkdir /usr/share/nginx/example.com/html -p
-vi /etc/nginx/sites-available/example.com.conf
-ln -s /etc/nginx/sites-available/example.com.conf /etc/nginx/conf.d/
-vi /etc/nginx/nginx.com # comment out the root in default server block (troubleshooting)
-systemctl reload nginx
-```
-
-## PHP-FPM setup
-
-### Change user in configuration (nginx):
-
-`vi /etc/php-fpm.d/www.conf`
-
-`systemctl enable php-fpm`
-
-`systemctl restart php-fpm`
-
-### PHP-OPCache setup
-
-`vi /etc/php.d/10-opcache.ini`
-
-```
-opcache.enable_cli=1
-opcache.memory_consumption=128
-opcache.interned_strings_buffer=8
-opcache.max_accelerated_files=4000
-opcache.revalidate_freq=60
-```
-
-`systemctl restart php-fpm`
-
-`systemctl reload nginx`
-
-### phpMyAdmin setup
-
-`dnf install phpmyadmin `
-
-`ln -s /usr/share/phpMyAdmin/ /usr/share/nginx/hosting.namenode.xyz/dbpma`
-
-`chown -R nginx:nginx /var/lib/php/session`
-
-`chown -R nginx:nginx /var/lib/phpMyAdmin`
-
-`chown -R nginx:nginx /etc/phpMyAdmin`
-
-`vi /etc/phpMyAdmin/config.inc.php`
-
-```
-$cfg['Servers'][$i]['AllowNoPassword'] = false;
-$cfg['Servers'][$i]['AllowRoot'] = false;
-
-$cfg['TempDir'] = '/var/lib/phpMyAdmin/temp';
-
-```
-`systemctl reload php-fpm`
-
-`systemctl reload nginx`
-
-
-### Securing phpMyAdmin further
-```
-vi pass-infile ## make a password for openssl to encrypt - one line no spaces
-```
-```
-openssl passwd -in pass-infile ## Copy the output (your encrypted password)
-```
-```
-vi /etc/nginx/pma_pass # Create a user/pass pair for the authentication gateway.
-```
-### Format:
-```
-user:p@s$w0Rd # one line
-```
-### Add the required "dbpma" section
-
-`vi /etc/nginx/sites-available/example.com.conf`
-
-`systemctl reload nginx`
-
-[Install and secure PMA with NGINX Ubuntu 18.04](https://www.digitalocean.com/community/tutorials/how-to-install-and-secure-phpmyadmin-with-nginx-on-an-ubuntu-18-04-server)
-
-
-## Cockpit Setup
-
-`vi /etc/cockpit/cockpit.conf`
-
-`vi /etc/nginx/sites-available/example.com.conf`
-
-[Proxying Cockpit over NGINX](https://github.com/cockpit-project/cockpit/wiki/Proxying-Cockpit-over-nginx)
-
-[Reverse proxy Cockpit over NGINX](https://www.freesoftwareservers.com/display/FREES/Reverse+Proxy+Cockpit+over+NGinX)
-
-
-## Certbot setup (Examples)
-```
-certbot --nginx -d example.com -d www.example.com
-
-certbot --nginx --agree-tos -d example.com -d www.example.com --email your-email-address
-
-certbot --nginx --agree-tos --redirect --hsts --staple-ocsp --must-staple -d example.com -d www.example.com --email your-email-address
-```
-
-`$ EDITOR=vim crontab -e`
-
-```
-25 2 * * 0 /usr/bin/certbot renew --quiet # Every Sunday 2:25am
-```

README.md

@@ -3,6 +3,8 @@
 #### ***A compendium of various technical information.***
 
 ## Cheat Sheets
+- [AWK]((https://git.namenode.xyz/CSnap/cheetsheetz/src/branch/main/awk.md)
+- [AWKWARD- AWK and SED examples](https://git.namenode.xyz/CSnap/cheetsheetz/src/branch/main/awkward.md))
 - [BASH - The Bourne Again Shell](https://git.namenode.xyz/CSnap/cheetsheetz/src/branch/main/BASH.md)
 - [CSS - Cascading Style Sheets](https://git.namenode.xyz/CSnap/cheetsheetz/src/branch/main/CSS.md)
 - [HTML - The HyperText Markup Language](https://git.namenode.xyz/CSnap/cheetsheetz/src/branch/main/HTML.md)
@@ -12,6 +14,7 @@
 - [Perl - Practical Extraction and Reporting Language](https://git.namenode.xyz/CSnap/cheetsheetz/src/branch/main/perl.md)
 - [PHP - Proper Hypertext Pre-processor](https://git.namenode.xyz/CSnap/cheetsheetz/src/branch/main/PHP.md)
 - [Python - High-level, general-purpose programming language](https://git.namenode.xyz/CSnap/cheetsheetz/src/branch/main/python.md)
+- [SED - The Stream Editor](- [AWK]((https://git.namenode.xyz/CSnap/cheetsheetz/src/branch/main/sed.md))
 - [SQL - Structured Query Language](https://git.namenode.xyz/CSnap/cheetsheetz/src/branch/main/SQL.md)
 
 ## Guides

awk.md

@@ -0,0 +1,158 @@
+
+# AWK Cheat Sheet
+
+## Table of Contents
+
+1. [AWK Basics](#awk-basics)
+2. [Patterns and Actions](#patterns-and-actions)
+3. [Variables](#variables)
+4. [Operators](#operators)
+5. [Built-in Variables](#built-in-variables)
+6. [Control Structures](#control-structures)
+7. [Functions](#functions)
+8. [Text Processing](#text-processing)
+9. [Regular Expressions](#regular-expressions)
+10. [Arrays](#arrays)
+11. [User-Defined Functions](#user-defined-functions)
+12. [Command Execution](#command-execution)
+
+## AWK Basics
+
+### Print Lines
+
+```awk
+awk '{print}' filename
+```
+
+### Print Specific Column
+
+```awk
+awk '{print $2}' filename
+```
+
+### Filter with Condition
+
+```awk
+awk '$1 > 10 {print}' filename
+```
+
+## Patterns and Actions
+
+```awk
+# Pattern with Action
+pattern1 { action1 }
+pattern2 { action2 }
+```
+
+## Variables
+
+```awk
+# Assigning Variables
+variable = value
+
+# Accessing Variables
+print variable
+```
+
+## Operators
+
+```awk
+# Arithmetic Operators
++, -, *, /, %
+
+# Relational Operators
+==, !=, >, <, >=, <=
+
+# Logical Operators
+&&, ||
+```
+
+## Built-in Variables
+
+```awk
+# NR: Record Number
+NR > 1 {print "Line Number: " NR}
+
+# NF: Number of Fields
+{print "Number of Fields: " NF}
+```
+
+## Control Structures
+
+```awk
+# if Statement
+if (condition) {
+    # Commands
+}
+
+# if-else Statement
+if (condition) {
+    # Commands for true condition
+} else {
+    # Commands for false condition
+}
+```
+
+## Functions
+
+```awk
+# Built-in Functions
+{
+    result = sqrt(9)
+    print "Square Root: " result
+}
+```
+
+## Text Processing
+
+### Field Separator
+
+```awk
+# Change Field Separator
+awk -F',' '{print $2}' filename
+```
+
+### Output Formatting
+
+```awk
+# Formatting Output
+awk '{printf "Name: %-10s Age: %d\n", $1, $2}' filename
+```
+
+## Regular Expressions
+
+```awk
+# Match Pattern
+awk '/pattern/ {print}' filename
+```
+
+## Arrays
+
+```awk
+# Declare an Array
+array[1] = "apple"
+array[2] = "banana"
+
+# Access Array Element
+print array[1]
+```
+
+## User-Defined Functions
+
+```awk
+# Define a Function
+function my_function(parameter) {
+    # Commands
+}
+
+# Call the Function
+my_function(value)
+```
+
+## Command Execution
+
+```awk
+# Execute Command
+awk '{cmd = "echo " $1; system(cmd)}' filename
+```
+

awkward.md

@@ -0,0 +1,700 @@
+# AWK and SED Examples
+
+These examples explore the combined use of AWK and SED for text processing tasks. 
+
+## Example 1: AWK and SED for Text Transformation
+
+### Input File (input.txt)
+
+```
+John Doe,25,Engineer
+Jane Smith,30,Designer
+Bob Johnson,22,Developer
+```
+
+### Goal
+
+We want to transform the CSV data into a formatted table with headers.
+
+### Solution
+
+```bash
+awk -F',' '{printf "%-15s %-3s %-10s\n", $1, $2, $3}' input.txt | sed '1i\
+Name            Age Job\
+--------------- --- ----------'
+```
+
+### Output
+
+```
+Name            Age Job
+--------------- --- ----------
+John Doe        25  Engineer
+Jane Smith      30  Designer
+Bob Johnson     22  Developer
+```
+
+## Example 2: AWK and SED for Selective Printing
+
+### Input File (input.txt)
+
+```
+apple
+banana
+cherry
+date
+```
+
+### Goal
+
+Print lines containing "a" or "e" using AWK and SED.
+
+### Solution
+
+```bash
+awk '/a|e/' input.txt | sed -n '/a\|e/p'
+```
+
+### Output
+
+```
+apple
+banana
+date
+```
+
+## Example 3: AWK and SED for Filtering and Sorting
+
+### Input File (input.txt)
+
+```
+apple,5
+banana,2
+cherry,8
+date,1
+```
+
+### Goal
+
+Filter lines with the second column greater than 2, sort by the second column, and add a header.
+
+### Solution
+
+```bash
+awk -F',' '$2 > 2' input.txt | sort -t',' -k2n | sed '1i\
+Fruit,Quantity'
+```
+
+### Output
+
+```
+Fruit,Quantity
+apple,5
+cherry,8
+```
+
+## Example 4: AWK and SED for Text Extraction
+
+### Input File (input.txt)
+
+```
+Lorem ipsum dolor sit amet, consectetur adipiscing elit.
+Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
+```
+
+### Goal
+
+Extract sentences containing the word "sed" and replace "sed" with "AWK".
+
+### Solution
+
+```bash
+awk 'BEGIN{RS="\\."} /sed/' input.txt | sed 's/sed/AWK/g'
+```
+
+### Output
+
+```
+Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua
+```
+
+## Example 5: AWK and SED for HTML Tag Extraction
+
+### Input File (input.html)
+
+```html
+<div class="container">
+    <p>This is a paragraph.</p>
+    <a href="https://example.com">Visit our website</a>
+</div>
+```
+
+### Goal
+
+Extract and list all HTML tags present in the file.
+
+### Solution
+
+```bash
+sed -n 's/<[^>]*>//p' input.html | awk '{print tolower($0)}'
+```
+
+### Output
+
+```
+div class="container"
+p
+a href="https://example.com"
+/a
+```
+
+## Example 6: AWK and SED for JSON Formatting
+
+### Input File (input.json)
+
+```json
+{
+    "name": "John Doe",
+    "age": 30,
+    "city": "New York"
+}
+```
+
+### Goal
+
+Format the JSON to be human-readable using AWK and SED.
+
+### Solution
+
+```bash
+awk -v RS= '{$1=$1}1' input.json | sed 's/":"/": "/g; s/{/{\n/g; s/}/\n}/g'
+```
+
+### Output
+
+```
+{
+    "name": "John Doe",
+    "age": 30,
+    "city": "New York"
+}
+```
+
+## Example 7: AWK and SED for Log Analysis
+
+### Input File (logfile.txt)
+
+```
+2023-01-15 10:23:15 INFO User login successful
+2023-01-15 10:30:42 ERROR Invalid password attempt
+2023-01-15 11:05:18 INFO User logout
+```
+
+### Goal
+
+Extract and format log entries containing "ERROR".
+
+### Solution
+
+```bash
+awk '/ERROR/' logfile.txt | sed 's/\([0-9]\{4\}-[0-9]\{2\}-[0-9]\{2\} [0-9]\{2\}:[0-9]\{2\}:[0-9]\{2\}\) \(ERROR .*\)/Timestamp: \1\n\2\n/'
+```
+
+### Output
+
+```
+Timestamp: 2023-01-15 10:30:42
+ERROR Invalid password attempt
+```
+
+## Example 8: AWK and SED for CSV Transformation
+
+### Input File (data.csv)
+
+```
+Name,Age,Occupation
+John,28,Engineer
+Jane,35,Designer
+Bob,22,Developer
+```
+
+### Goal
+
+Transform the CSV data into a tab-separated format.
+
+### Solution
+
+```bash
+awk -F',' '{printf "%s\t%s\t%s\n", $1, $2, $3}' data.csv | sed '1i\
+Name\tAge\tOccupation'
+```
+
+### Output
+
+```
+Name    Age     Occupation
+John    28      Engineer
+Jane    35      Designer
+Bob     22      Developer
+```
+
+## Example 9: AWK and SED for XML Tag Removal
+
+### Input File (data.xml)
+
+```xml
+<root>
+    <item>Apple</item>
+    <item>Banana</item>
+    <item>Cherry</item>
+</root>
+```
+
+### Goal
+
+Remove all XML tags and extract the content.
+
+### Solution
+
+```bash
+sed 's/<[^>]*>//g' data.xml | awk 'NF'
+```
+
+### Output
+
+```
+Apple
+Banana
+Cherry
+```
+
+## Example 10: AWK and SED for Markdown Table Conversion
+
+### Input File (table.md)
+
+```markdown
+| Name  | Age | Occupation  |
+|-------|-----|-------------|
+| John  | 28  | Engineer    |
+| Jane  | 35  | Designer    |
+| Bob   | 22  | Developer   |
+```
+
+### Goal
+
+Convert the Markdown table into a CSV format.
+
+### Solution
+
+```bash
+sed -n '/|/p' table.md | awk -F'|' '{gsub(/^[ \t]+|[ \t]+$/, "", $2); gsub(/^[ \t]+|[ \t]+$/, "", $3); gsub(/^[ \t]+|[ \t]+$/, "", $4); printf "%s,%s,%s\n", $2, $3, $4}'
+```
+
+### Output
+
+```
+Name,Age,Occupation
+John,28,Engineer
+Jane,35,Designer
+Bob,22,Developer
+```
+
+## Example 11: AWK and SED for HTML List Extraction
+
+### Input File (list.html)
+
+```html
+<ul>
+    <li>Apple</li>
+    <li>Banana</li>
+    <li>Cherry</li>
+</ul>
+```
+
+### Goal
+
+Extract and list items from an HTML unordered list.
+
+### Solution
+
+```bash
+sed -n '/<li>/s/<li>\(.*\)<\/li>/\1/p' list.html | awk '{print "- " $0}'
+```
+
+### Output
+
+```
+- Apple
+- Banana
+- Cherry
+```
+
+## Example 12: AWK and SED for YAML to JSON Conversion
+
+### Input File (data.yaml)
+
+```yaml
+name: John Doe
+age: 30
+city: New York
+```
+
+### Goal
+
+Convert YAML data into JSON format.
+
+### Solution
+
+```bash
+sed -n '/^[^#]/s/: /: "/p' data.yaml | awk '{printf "%s", $0} END {print "\""}' | sed 's/"/\\"/g' | awk 'BEGIN {print "{"} {print "  " $0} END {print "}"}'
+```
+
+### Output
+
+```
+{
+  name: "John Doe",
+  age: "30",
+  city: "New York"
+}
+```
+
+## Example 13: AWK and SED for Extracting URLs
+
+### Input File (text_with_urls.txt)
+
+```
+Visit our website: https://example.com
+For more information, check out: https://documentation.com
+```
+
+### Goal
+
+Extract and list all URLs from the text.
+
+### Solution
+
+```bash
+sed -n 's/.*\(https\?:\/\/[^ ]*\).*/\1/p' text_with_urls.txt | awk '!a[$0]++'
+```
+
+### Output
+
+```
+https://example.com
+https://documentation.com
+```
+
+## Example 14: AWK and SED for Data Filtering and Sorting
+
+### Input File (data.txt)
+
+```
+Name|Age|Occupation
+John|28|Engineer
+Jane|35|Designer
+Bob|22|Developer
+```
+
+### Goal
+
+Filter entries with Age greater than 25 and sort by Age.
+
+### Solution
+
+```bash
+awk -F'|' '$2 > 25' data.txt | sort -t'|' -k2n | sed '1i\
+Name|Age|Occupation'
+```
+
+### Output
+
+```
+Name|Age|Occupation
+Jane|35|Designer
+John|28|Engineer
+```
+
+## Example 15: AWK and SED for Line Reversal
+
+### Input File (reverse_me.txt)
+
+```
+Line 1
+Line 2
+Line 3
+```
+
+### Goal
+
+Reverse the order of lines in the file.
+
+### Solution
+
+```bash
+awk '{a[i++]=$0} END {for (j=i-1; j>=0;) print a[j--] }' reverse_me.txt | sed '1i\
+Reversed Lines'
+```
+
+### Output
+
+```
+Reversed Lines
+Line 3
+Line 2
+Line 1
+```
+
+## Example 16: AWK and SED for Word Frequency Analysis
+
+### Input File (text_analysis.txt)
+
+```
+apple orange banana
+banana apple orange
+orange banana apple
+```
+
+### Goal
+
+Count the frequency of each word and sort the results.
+
+### Solution
+
+```bash
+awk '{for(i=1; i<=NF; i++) words[$i]++} END {for(word in words) print word, words[word]}' text_analysis.txt | sort -k2n -r | sed '1i\
+Word Frequency'
+```
+
+### Output
+
+```
+Word Frequency
+banana 3
+apple 3
+orange 3
+```
+
+## Example 17: AWK and SED for JSON Pretty Printing
+
+### Input File (json_data.json)
+
+```json
+{"name":"John","age":30,"city":"New York"}
+```
+
+### Goal
+
+Format the JSON data for better readability.
+
+### Solution
+
+```bash
+awk -v RS= '{$1=$1}1' json_data.json | sed 's/":"/": "/g; s/{/{\n/g; s/}/\n}/g'
+```
+
+### Output
+
+```
+{
+  "name": "John",
+  "age": 30,
+  "city": "New York"
+}
+```
+
+## Example 18: AWK and SED for Extracting Email Addresses
+
+### Input File (emails.txt)
+
+```
+Contact us at: info@example.com
+For support, email support@example.com
+```
+
+### Goal
+
+Extract and list all email addresses from the text.
+
+### Solution
+
+```bash
+sed -n 's/.*\b\([a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}\)\b.*/\1/p' emails.txt | awk '!a[$0]++' | sed '1i\
+Email Addresses'
+```
+
+### Output
+
+```
+Email Addresses
+info@example.com
+support@example.com
+```
+
+## Example 19: Convert Markdown Headings to HTML
+
+### Input (markdown_headings.md)
+
+```markdown
+# Heading 1
+## Heading 2
+### Heading 3
+```
+
+### Goal
+
+Convert Markdown headings to HTML headings.
+
+### Solution
+
+```bash
+sed -n 's/^# \(.*\)$/\<h1\>\1\<\/h1\>/p; s/^## \(.*\)$/\<h2\>\1\<\/h2\>/p; s/^### \(.*\)$/\<h3\>\1\<\/h3\>/p' markdown_headings.md
+```
+
+### Output
+
+```html
+<h1>Heading 1</h1>
+<h2>Heading 2</h2>
+<h3>Heading 3</h3>
+```
+
+## Example 20: Convert Markdown Lists to HTML
+
+### Input (markdown_lists.md)
+
+```markdown
+- Item 1
+- Item 2
+  - Subitem A
+  - Subitem B
+```
+
+### Goal
+
+Convert Markdown lists to HTML lists.
+
+### Solution
+
+```bash
+awk '/^-/ {gsub(/^-/, "<li>"); print "<ul>"; print $0} !/^-/ {gsub(/^ /, ""); print $0 "</li>"} END {print "</ul>"}' markdown_lists.md
+```
+
+### Output
+
+```html
+<ul>
+<li>Item 1</li>
+<li>Item 2<ul><li>Subitem A</li><li>Subitem B</li></ul></li>
+</ul>
+```
+
+## Example 21: Convert Bold and Italic Markdown to HTML
+
+### Input (markdown_bold_italics.md)
+
+```markdown
+**Bold Text** *Italic Text*
+```
+
+### Goal
+
+Convert Markdown bold and italic text to HTML.
+
+### Solution
+
+```bash
+sed -e 's/\*\*\(.*\)\*\*/\<strong\>\1\<\/strong\>/g' -e 's/\*\([^*]*\)\*/\<em\>\1\<\/em\>/g' markdown_bold_italics.md
+```
+
+### Output
+
+```html
+<strong>Bold Text</strong> <em>Italic Text</em>
+```
+
+## Example 22: Reverse the Order of Lines
+
+### Input (original_order.txt)
+
+```
+Line 1
+Line 2
+Line 3
+```
+
+### Goal
+
+Reverse the order of lines in the file.
+
+### Solution
+
+```bash
+awk '{a[i++]=$0} END {for (j=i-1; j>=0;) print a[j--] }' original_order.txt
+```
+
+### Output
+
+```
+Line 3
+Line 2
+Line 1
+```
+
+## Example 23: Sort Lines Alphabetically
+
+### Input (unsorted_lines.txt)
+
+```
+Banana
+Apple
+Cherry
+```
+
+### Goal
+
+Sort lines alphabetically.
+
+### Solution
+
+```bash
+sort unsorted_lines.txt
+```
+
+### Output
+
+```
+Apple
+Banana
+Cherry
+```
+
+## Example 24: Sort Lines by Line Length
+
+### Input (lines_by_length.txt)
+
+```
+Short
+VeryLongLineWithManyCharacters
+MediumLength
+```
+
+### Goal
+
+Sort lines by their length.
+
+### Solution
+
+```bash
+awk '{ print length, $0 | "sort -n"}' lines_by_length.txt | cut -d ' ' -f2-
+```
+
+### Output
+
+```
+Short
+MediumLength
+VeryLongLineWithManyCharacters
+```
+

regex.md

@@ -0,0 +1,79 @@
+# Regular Expressions (Regex) Cheat Sheet
+
+In this cheat sheet, we'll explore common Regular Expressions (regex) patterns and their meanings.
+
+## Table of Contents
+
+1. [Anchors](#anchors)
+2. [Character Classes](#character-classes)
+3. [Quantifiers](#quantifiers)
+4. [Grouping and Capturing](#grouping-and-capturing)
+5. [Alternation](#alternation)
+6. [Assertions](#assertions)
+7. [Modifiers](#modifiers)
+8. [Escape Characters](#escape-characters)
+9. [Special Characters](#special-characters)
+
+## Anchors
+
+- `^`: Asserts the start of a line.
+- `$`: Asserts the end of a line.
+- `\b`: Asserts a word boundary.
+- `\B`: Asserts a non-word boundary.
+
+## Character Classes
+
+- `.`: Matches any single character except a newline.
+- `[abc]`: Matches any one of the characters a, b, or c.
+- `[^abc]`: Matches any character except a, b, or c.
+- `[a-z]`: Matches any lowercase letter.
+- `[A-Z]`: Matches any uppercase letter.
+- `[0-9]`: Matches any digit.
+- `\d`: Matches any digit (short for `[0-9]`).
+- `\D`: Matches any non-digit.
+- `\w`: Matches any word character (alphanumeric + underscore).
+- `\W`: Matches any non-word character.
+- `\s`: Matches any whitespace character.
+- `\S`: Matches any non-whitespace character.
+
+## Quantifiers
+
+- `*`: Matches 0 or more occurrences of the preceding character or group.
+- `+`: Matches 1 or more occurrences of the preceding character or group.
+- `?`: Matches 0 or 1 occurrence of the preceding character or group.
+- `{n}`: Matches exactly n occurrences of the preceding character or group.
+- `{n,}`: Matches n or more occurrences of the preceding character or group.
+- `{n,m}`: Matches between n and m occurrences of the preceding character or group.
+
+## Grouping and Capturing
+
+- `(...)`: Groups patterns together. Captures the matched text.
+- `(?:...)`: Groups patterns together without capturing.
+- `\1`, `\2`, ...: Refers to the first, second, etc. captured group.
+
+## Alternation
+
+- `|`: Acts like a logical OR. Matches the pattern before or after the pipe.
+
+## Assertions
+
+- `(?=...)`: Positive lookahead assertion.
+- `(?!...)`: Negative lookahead assertion.
+- `(?<=...)`: Positive lookbehind assertion.
+- `(?<!...)`: Negative lookbehind assertion.
+
+## Modifiers
+
+- `i`: Case-insensitive matching.
+- `g`: Global matching (find all matches).
+- `m`: Multiline matching (`^` and `$` match the start/end of each line).
+
+## Escape Characters
+
+- `\`: Escapes a special character, allowing it to be treated as a literal.
+
+## Special Characters
+
+- `*`, `+`, `?`, `{`, `}`, `|`, `()`, `[]`, `.`, `\`: Special characters with their literal meanings when escaped.
+
+

sed.md

@@ -0,0 +1,132 @@
+# Comprehensive SED Cheat Sheet
+
+## Table of Contents
+
+1. [SED Basics](#sed-basics)
+2. [Print Operations](#print-operations)
+3. [Substitution](#substitution)
+4. [Deletion](#deletion)
+5. [Insertion](#insertion)
+6. [Append and Replace](#append-and-replace)
+7. [Selective Printing](#selective-printing)
+8. [Text Formatting](#text-formatting)
+9. [Multiple Commands](#multiple-commands)
+10. [Regular Expressions](#regular-expressions)
+11. [Grouping and Backreferences](#grouping-and-backreferences)
+12. [File In-Place Editing](#file-in-place-editing)
+13. [SED Scripts](#sed-scripts)
+
+## SED Basics
+
+### Basic Syntax
+
+```bash
+sed 'command' filename
+```
+
+### In-Place Editing
+
+```bash
+sed -i 'command' filename
+```
+
+## Print Operations
+
+```bash
+# Print All Lines
+sed -n 'p' filename
+
+# Print Line Numbers
+sed -n '10p' filename
+
+# Print Range of Lines
+sed -n '5,10p' filename
+```
+
+## Substitution
+
+```bash
+# Substitute Text
+sed 's/pattern/replacement/' filename
+
+# Global Substitution
+sed 's/pattern/replacement/g' filename
+```
+
+## Deletion
+
+```bash
+# Delete Matching Lines
+sed '/pattern/d' filename
+
+# Delete Lines by Number
+sed '5d' filename
+```
+
+## Insertion
+
+```bash
+# Insert Line Before Matching Pattern
+sed '/pattern/i new_line' filename
+```
+
+## Append and Replace
+
+```bash
+# Append Line After Matching Pattern
+sed '/pattern/a new_line' filename
+
+# Replace Line with New Text
+sed '/pattern/c new_line' filename
+```
+
+## Selective Printing
+
+```bash
+# Print Lines Matching Pattern
+sed -n '/pattern/p' filename
+```
+
+## Text Formatting
+
+```bash
+# Convert to Uppercase
+sed 'y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/' filename
+```
+
+## Multiple Commands
+
+```bash
+# Execute Multiple Commands
+sed -e 'command1' -e 'command2' filename
+```
+
+## Regular Expressions
+
+```bash
+# Use Regular Expressions
+sed '/^pattern/s/replacement/' filename
+```
+
+## Grouping and Backreferences
+
+```bash
+# Use Grouping and Backreferences
+sed 's/\(pattern1\)\(pattern2\)/\2\1/' filename
+```
+
+## File In-Place Editing
+
+```bash
+# In-Place Editing with Backup
+sed -i.bak 's/pattern/replacement/' filename
+```
+
+## SED Scripts
+
+```bash
+# Create and Use SED Script
+echo 's/pattern/replacement/' > myscript.sed
+sed -f myscript.sed filename
+```
+