Entries this day: getting-my-perl-journal-markdown-parser-working highlight-testaroo

getting my perl journal markdown parser working

Nearly four years ago, I wrote about my desire to get my old Perl journal to correctly display my recent journal entries which are in markdown files.

I've consistently used ~/journal/yyyy/mm/ddtitle-here.ext as the filename, where ext is either txt, html, or md.

I couldn't get the Perl markdown processors installed on Dreamhost, so I asked ChatGPT to write one for me. This is what we've got so far:

# Text/RobMiniMarkdown.pm
package Text::RobMiniMarkdown;
use strict;
use warnings;

sub new { bless {}, shift }

my @para_buffer;

sub flush_paragraph {
    my $joined = join ' ', @para_buffer;
    @para_buffer = ();
    return "<p>$joined</p>\n" if $joined =~ /\S/;
    return '';
}

sub markdown {
    my ($self, $text) = @_;
    my @lines = split /\n/, $text;
    my $html = "";
    my $in_code_block = 0;
    my $in_list = 0;
    my $list_type = '';
    my $in_frontmatter = 0;
    my $in_html_block = 0;
    my $in_indented_code = 0;
    my @html_block;
    my @code_buffer;
    my @indented_buffer;

    foreach my $line (@lines) {
        # Skip YAML frontmatter
        if ($line =~ /^---\s*$/) {
            $in_frontmatter = !$in_frontmatter;
            next;
        }
        next if $in_frontmatter;

        if ($line =~ /^```/) {
            if ($in_code_block) {
                $html .= join('', @code_buffer) . "</pre>\n";
                @code_buffer = ();
            } else {
                $html .= "<pre>";
            }
            $in_code_block = !$in_code_block;
            next;
        }
        if ($in_code_block) {
            push @code_buffer, "$line\n";
            next;
        }

        # HTML block: detect opening tag
        if (!$in_html_block && $line =~ /^\s*<(\w+)[^>]*?>\s*$/) {
            $in_html_block = 1;
            @html_block = ($line);
            next;
        }

        if ($in_html_block) {
            push @html_block, $line;

            # If we detect the closing tag, flush
            if ($line =~ /<\/\w+>\s*$/) {
                $html .= join("\n", @html_block) . "\n";
                $in_html_block = 0;
                @html_block = ();
            }
            next;
        }

        # Indented code blocks
        if ($line =~ /^ {4,}/) {
            if (!$in_indented_code) {
                $in_indented_code = 1;
                @indented_buffer = ();
            }
	    $line =~ s/^ {4}//;   # remove four spaces from beginning of each line indented with four or more spaces
            push @indented_buffer, "$line\n";
            next;
        }

        if ($in_indented_code) {
            $html .= "<pre>" . join('', @indented_buffer) . "</pre>\n";
            $in_indented_code = 0;
            @indented_buffer = ();
        }

        # Headings
        if ($line =~ /^(#{1,6})\s+(.*)/) {
	    $html .= flush_paragraph();
            my $level = length($1);
            $html .= "<h$level>$2</h$level>\n";
            next;
        }

        # Horizontal rule
        if ($line =~ /^\s*(\*\*\*|---|___)\s*$/) {
	    $html .= flush_paragraph();
            $html .= "<hr/>\n";
            next;
        }

        # Blockquote
        if ($line =~ /^>\s?(.*)/) {
	    $html .= flush_paragraph();
            $html .= "<blockquote>$1</blockquote>\n";
            next;
        }

        # Unordered list
        if ($line =~ /^\s*[-+*]\s+(.*)/) {
	    $html .= flush_paragraph();
            if (!$in_list || $list_type ne 'ul') {
                $html .= "</$list_type>\n" if $in_list;
                $html .= "<ul>\n";
                $in_list = 1;
                $list_type = 'ul';
            }
            $html .= "  <li>$1</li>\n";
            next;
        }

        # Ordered list
        if ($line =~ /^\s*\d+\.\s+(.*)/) {
	    $html .= flush_paragraph();
            if (!$in_list || $list_type ne 'ol') {
                $html .= "</$list_type>\n" if $in_list;
                $html .= "<ol>\n";
                $in_list = 1;
                $list_type = 'ol';
            }
            $html .= "  <li>$1</li>\n";
            next;
        }

        # End list if current line isn't a list item
        if ($in_list and $line !~ /^\s*([-+*]|\d+\.)\s+/) {
	    $html .= flush_paragraph();
            $html .= "</$list_type>\n";
            $in_list = 0;
            $list_type = '';
        }

        # Tables (simple row)
        if ($line =~ /^\s*\|.*\|\s*$/) {
	    $html .= flush_paragraph();
            $html .= "<div class=\"table-row\">$line</div>\n";
            next;
        }

        # Inline code
        $line =~ s/`(.*?)`/<code>$1<\/code>/g;

        # Bold
        $line =~ s/\*\*(.*?)\*\*/<strong>$1<\/strong>/g;

        # Italic
        $line =~ s/(?<!\*)\*(.*?)\*(?!\*)/<em>$1<\/em>/g;

        # Links and images
        $line =~ s/!\[([^\]]*)\]\(([^\)]+)\)/<img alt="$1" src="$2" \/>/g;
        $line =~ s/\[([^\]]+)\]\(([^\)]+)\)/<a href="$2">$1<\/a>/g;

        # Paragraph (default case)
        if ($line =~ /^\s*$/) {
            $html .= flush_paragraph();
        } else {
            push @para_buffer, $line;
        }

    }

    # Close any open list
    $html .= "</$list_type>\n" if $in_list;

    # Final flush, just in case the file ends with indented code
    if ($in_indented_code) {
        $html .= "<pre>" . join('', @indented_buffer) . "</pre>\n";
    }

    return $html;
}

1;

And it's working pretty well!

To Do:

• Add the newer journal URL of this entry down below
• Ensure these lists show up correctly in the Hugo journal (which I plan to stop using *soon* (haha)"

1. Copy this file to my Perl journal directory
2. Confirm these lists show up correctly in my Perl journal
3. Post RobMiniMarkdown.pm on Github

• Confirm unordered lists show up correctly
• Confirm the Perl journal link to this file down below

The next big trick will be to allow journal entries to be visited at either URL

https://www.robnugen.com/journal/2025/04/16/getting-my-perl-journal-markdown-parser-working/

or

https://perl.robnugen.com/journal.pl?type=all&date=2025/04/16 (which can show multiple entries for that date)

highlight testaroo

Syntax Highlighting Test

This file includes code blocks in multiple languages to confirm Hugo's syntax highlighting.

Add this to Perl journal head tag:

HTML

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/styles/github.min.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/highlight.min.js"></script>
<script>hljs.highlightAll();</script>

Perl

my $name = "Rob";
print "Hello, $name!\n";

Bash

#!/bin/bash
echo "Hello from Bash"
ls -l /home/robnugen

PHP

<?php
echo "Hello from PHP!";
?>

JSON

{
  "name": "Rob",
  "role": "Connection Coach",
  "barefoot": true
}

No Language Specified

This is a code block with no language.

It should still render with a monospaced font,
but no syntax highlighting.