title: Comprehensive Markdown & GFM Syntax Reference
desc: A detailed guide to Markdown and GitHub Flavored Markdown (GFM) syntax, covering text formatting, lists, tables, code blocks, links, and footnotes.
date: 2026-05-27
draft: true
^---

<!-- THIS IS A COMMENT -->

This document serves as a comprehensive reference for Markdown and GitHub Flavored Markdown (GFM) syntax. It covers various formatting options, list types, table creation, code block usage, link formatting, and footnote implementation.

The purpose is to test and demonstrate the full range of Markdown features, ensuring that all syntax is correctly rendered and supported in the target environment. This includes both standard Markdown elements and GFM-specific extensions.

_This post was generated by AI for testing purposes_

---

## Images

![Alt text](https://picsum.photos/150)

---

## HTML in Markdown

<details>
  <summary>Click to expand HTML content</summary>
  <p>This is a block of HTML content embedded within Markdown. It can include any valid HTML elements, such as this <strong>bold text</strong> and this <em>italic text</em>.</p>
  <ul>
    <li>HTML List Item 1</li>
    <li>HTML List Item 2</li>
  </ul>
</details>

<iframe src="https://google.com" width="300" height="200"></iframe>
<br>^^ This **shouldn't** render as an iframe but should show the raw HTML code

---

## Text Formatting & Structure

*   **Bold:** **This text is bold** or __this is bold__.
*   **Italic:** *This text is italic* or _this is italic_.
*   **Strikethrough (GFM):** ~~This text is crossed out.~~
*   **Combined:** ***This text is bold and italic***.
*   **Inline Code:** Use single backticks for `console.log("Hello World")` inline.

### Hierarchy Example
> **Blockquotes:** Use blockquotes to highlight quotes, notes, or warnings.
> 
> "The best way to predict the future is to invent it."
> > Nested blockquotes are supported by adding an extra `>`.

---

## Lists

### Unordered (Bulleted)
*   Item 1
    *   Nested Item 1.1
    *   Nested Item 1.2
*   Item 2

### Ordered (Numbered)
1.  First item
2.  Second item
    1.  Nested ordered item
    2.  Another nested item
3.  Third item

### Task Lists (GFM)
- [x] Write the Markdown test template
- [ ] Implement features in production
- [ ] Review documentation

---

## Links and Autolinks

*   **Standard Link:** [Search Engine](https://www.google.com)
*   **Link with Tooltip:** [GitHub](https://github.com "Go to GitHub")
*   **Autolink (GFM):** https://nixos.org

---

## Tables (GFM)

| Feature | Standard Markdown | GFM Extension | Status |
| :--- | :---: | :---: | ---: |
| Tables | ✗ | ✓ | Implemented |
| Task Lists | ✗ | ✓ | Implemented |
| Autolinks | ✗ | ✓ | Native |
| Strikethrough | ✗ | ✓ | Implemented |

---

## Code Blocks with Syntax Highlighting

```bash
#!/usr/bin/env bash
set -euo pipefail

# Variables & string manipulation
NAME="world"
GREETING="Hello, ${NAME}!"
UPPER=${GREETING^^}
SLICE=${GREETING:0:5}
echo "$UPPER | $SLICE"

# Arrays
FRUITS=(apple banana cherry)
FRUITS+=(mango)
echo "${FRUITS[@]}"          # all elements
echo "${#FRUITS[@]}"         # length
echo "${FRUITS[@]:1:2}"      # slice

# Associative array
declare -A CONFIG=([host]="localhost" [port]="8080")
echo "${CONFIG[host]}:${CONFIG[port]}"

# Arithmetic
COUNT=0
(( COUNT += 5 ))
RESULT=$(( COUNT ** 2 ))
echo "$RESULT"

# Conditionals & test operators
FILE="/etc/hosts"
if [[ -f "$FILE" && -r "$FILE" ]]; then
  echo "readable"
elif [[ -e "$FILE" ]]; then
  echo "exists but not readable"
else
  echo "not found"
fi

# Case
case "$NAME" in
  world|earth) echo "planet" ;;
  *) echo "unknown" ;;
esac

# Loops
for fruit in "${FRUITS[@]}"; do
  echo "fruit: $fruit"
done

for (( i=0; i<3; i++ )); do
  echo "i=$i"
done

WHILE=3
while (( WHILE-- > 0 )); do
  echo "while: $WHILE"
done

# Functions with local vars & return codes
greet() {
  local name=${1:-"stranger"}
  local -r greeting="Hi, $name!"
  echo "$greeting"
  return 0
}
greet "$NAME"

# Command substitution & process substitution
DATE=$(date +%Y-%m-%d)
DIFF=<(echo "foo") 
echo "Today: $DATE"

# Here-doc
cat <<EOF
Multiline
  text block
EOF

# Pipelines, redirection & traps
trap 'echo "exiting"; exit 1' ERR
echo "hello" | tr '[:lower:]' '[:upper:]' > /dev/null 2>&1

# Parameter expansion: default, error, replace
echo "${UNSET:-default}"
echo "${GREETING/Hello/Hey}"
echo "${FILE##*/}"   # basename
echo "${FILE%/*}"    # dirname
```