Using `git diff-index --check`.git/hooks/pre-commit

To ensure that your article is at least 800 words long, covers the key concepts in detail, and is properly formatted, follow these steps:

1. Provide a detailed context topic, covering the key concepts with subtitles (use H2, H3, etc.). Use <p></p> tags for paragraphs.

2. Enclose code blocks with <code> tags. The content inside code blocks must be properly formatted according to the programming language, including indentation and tabulation needed. Exclude the H1 tag title, which should be provided separately.

3. End the article with a summary and references in an HTML unordered list (<ul>). Specify the types of references included (books, articles, online resources). Do not use page layout tags like <div>, <hr>, etc. Avoid mentioning multipage articles; the purpose is to generate a single page.

4. Generate plain HTML output. Ensure the output HTML is valid.

5. To automate this process using a Git hook, you can use the following command:

cp .git/hooks/pre-commit.sample .git/hooks/pre-commit

Then, modify the .git/hooks/pre-commit file as follows:

#!/bin/sh

git diff --cached --diff-index --ignore-space-at-eol --ignore-blank-lines | grep -E '^([A-Za-z0-9\/\-\_]+)\.md$' | while read file; do
    cat $file | grep -E '^(#|<h[2-6]>|<p>|<code>|</code>|<ul>|</ul>|<li>|<a>' | wc -l
    if [ $(cat $file | grep -E '^(#|<h[2-6]>|<p>|<code>|</code>|<ul>|</ul>|<li>|<a>' | wc -l) -lt 800 ]; then
        echo "Error: Article is less than 800 words long."
        exit 1
    fi
done

exit 0

This script checks the number of lines containing headers (H1-H6), paragraphs (<p>), code blocks (<code>), unordered lists (<ul>), list items (<li>), and links (<a>) in each .md file, and exits with an error if the total is less than 800.