NAME

bookmark-feed - generate a feed from Markdown files

SYNOPSIS

bookmark-feed markdown-files... feed-file

DESCRIPTION

The bookmark-feed turns external links in a bunch of Markdown pages into a RSS feed.

The arguments are all file names. All but the last file are existing Markdown files to be checked for new links. The last file is the resulting feed file. It is overwritten.

If you keep bookmarks in Markdown files, they might be big or small. A simple setup might just be a list of links:

* [Alex Schroeder](https://alexschroeder.ch/)
* [Emacs Wiki](https://www.emacswiki.org/)

Or your might be using quotes, like this:

> Seventy eight percent of Americans—including 66% of Republicans—are
> concerned about climate change, a number that has increased dramatically
> in the last 3 years. … The lack of public discussion reinforces the norm
> that others are not concerned and hampers the likelihood of collective
> organization to address climate change. Misconceptions take on an even
> larger significance when we remember that those in positions of power are
> people too. – [To create serious movement on climate change, we must
> dispel the myth of
> indifference](https://www.nature.com/articles/s41467-022-32413-x) (2022),
> by Cynthia McPherson Frantz, in Nature Communications

When parsing Markdown files, each link with a schema of http, https, gemini or gopher is an "item". Each item has a link, a link text, and a description. The description is the paragraph, block quote or list item that contains the link.

Note that only a single paragraph or list item is used. In the following example, the paragraph break means that the first sentence is not used.

> This is a paragraph.
>
> This is another paragraph. – [Link](https://example.org/)

Links in a paragraph that ends in a colon are ignored. The goal is to ignore the first paragraph in the following example:

The [foo](http://example.org/) said:

> It's terrible. – [bar](http://example.com/)

This means that the following would produce no item because the paragraph with the link ends in a colon and the paragraph with the quote contains no link:

The [foo](http://example.org/) said:

> It's terrible.

The following would also produce no item since the paragraph with the link ends in a colon and the list items contain no link.

The [foo](http://example.org/) said:

- something
- another thing

NOTES

The bookmarks have no timestamps: There is no date on which a particular link was added to the Markdown file. This is where the database comes in. Every time the program runs, new links are added to the database with the last-modified date of the file the link was found in. Therefore, if a file has multiple new links between two runs, the new links all share the same timestamp.

This also means that a subsequent run with fewer Markdown files doesn't necessarily remove items from the feed. The items in the Markdown files are added to the database and the feed is produced from the database. The old items from Markdown files that are no longer supplied or items that were deleted from the Markdown files remain in the database. If you need to remove items, you must remove them from the database directly.

FILES

The name of the SQLite database file is computed by removing the suffix .rss from the feed file and appending the suffix .db. It contains a single table called items with columns date, url, title and description.

Open the file:

sqlite3 bookmarks.db

Select the items created in the last 24h:

select * from items where date >= date('now', '-1 day');

Delete the item containing the phrase "The whole AI thing":

delete from items where description like '%The whole AI thing%';

Delete items older than 60 days:

delete from items where date < date('now', '-60 day');

EXAMPLES

This adds new links to a feed called bookmarks.rss:

bookmark-feed *-bookmarks.md *_Bookmarks.md bookmarks.rss

The name of the database file for all the seen links is derived from the feed filename: bookmarks.db.

REFERENCES

RSS 2.0 Specification, https://cyber.harvard.edu/rss/rss.html

App::BookmarkFeed

cpanm App::BookmarkFeed

perl -MCPAN -e shell
install App::BookmarkFeed