commit a9c4f75f96eda90f0163b308d8c9b2f9ec895eb8
parent 4056cc421d02e7b8df426551954814f15195afa9
Author: Sebastiano Tronto <sebastiano@tronto.net>
Date: Sat, 4 Jun 2022 00:29:27 +0200
Added blog post
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diff --git a/src/blog/2022-06-04-gemini/gemini.md b/src/blog/2022-06-04-gemini/gemini.md
@@ -0,0 +1,190 @@
+# The gemini protocol
+
+My website is also available as a *gemini capsule* at
+[gemini://tronto.net](gemini://tronto.net).
+Can't open this link? Of course, you'll need a *gemini* browser for that!
+
+[Gemini](https://gemini.circumlunar.space) is a very young (2019) internet
+protocol similar to the mcuh more famous
+[HTTP](https://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol), with
+the design goal of being much simpler.
+Gemini pages are written in *gemtext*, a very simple markup language that
+offers headers, hyperlinks, lists and little more - notably, there is no
+inline formatting.
+
+**Disclaimer**: I am not a networking expert, so I will keep this article
+at a very basic level. Nonetheless I may end up writing wrong or inaccurate
+things. If you know this stuff better than me and you spot a mistake, feel
+free to [send me an email](mailto:sebastiano@tronto.net).
+
+## Protocols: gemini:// and http://
+In the context of computer networks, a *protocol* is a set of rules that
+describes how two different machines should communicate to exchange data.
+If you are viewing this page in a normal web browser, the address in your
+address bar probably starts with `http://` (or `https://`, but let's pretend
+they are the same thing). This means that your device is communicating with
+the server where I have uploaded this page using the *Hypertext Transfer
+Protocol*. Concretely, your browser has sent the server a message such as
+
+```
+GET /blog/index.html HTTP/1.1
+Host: sebastiano.tronto.net
+```
+
+And the server has replied something like
+
+```
+HTTP/1.1 200 OK
+Connection: keep-alive
+Content-Length: 1131
+Content-Type: text/html
+Date: Fri, 03 Jun 2022 14:34:22 GMT
+Last-Modified: Sun, 29 May 2022 11:15:55 GMT
+Server: OpenBSD httpd
+
+<!doctype html>
+<html lang="en">
+<head>
+ <title> Blog | Sebastiano Tronto </title>
+
+(...Some more stuff...)
+
+</html>
+```
+
+So there is some garbage that you don't care about (your browser does),
+plus the actual content that you want to view. What exact garbage your
+browser and the server should exchange before one ships actual content
+to the other is exactly what the protocol defines. Calling it "garbage"
+is a bit unfair, because there can be some useful information: for example,
+when the page was last modified, so if your browser has already seen and
+cached this page it does not need to download it again, but there could
+be more stuff such as error messages or redirection paths.
+
+In contrast, a gemini browser might send a request that looks like
+
+```
+gemini://tronto.net/blog/index.gmi
+```
+
+To which a gemini server would respond simply
+
+```
+20 text/gemini;
+# Blog
+
+(...Some more stuff...)
+```
+
+Very briefly, this is how the two protocols work. You might be wondering how
+exactly your browser is sending and receiving this information. Well, http
+(and gemini) sit on top of other protocols which describe exactly this. These
+other protocols in turn are on top of other protocols and... basically,
+[it's protocols all the way down](https://en.wikipedia.org/wiki/Internet_protocol_suite).
+
+(If you are curious where I got the server responses from: the UNIX command
+`curl` and the gemini browser [`gmni`](https://git.sr.ht/~sircmpwn/gmni)
+have a `-i` option that allows to see the messages received from the server.)
+
+## The gemtext markup language
+
+Web pages are usually sent to your browser in
+[HTML](https://en.wikipedia.org/wiki/HTML) format. There are plenty of
+resources to learn how HTML works, so I will not explain it here.
+Very briefly,
+using tag pairs such as `<h1></h1>`, `<p></p>` or `<a href="..."></a>`,
+an html file tells your browser how to display its content. It may
+also embed images, videos or even executable scripts.
+
+Gemtext plays the same role for gemini pages, but it has (by design)
+a much more restricted feature set. It's syntax is somewhat similar to
+[Markdown](https://en.wikipedia.org/wiki/Markdown), another markup language.
+For example, headings and (unordered) lists work in the same way:
+
+```
+# A title
+## A second-level heading
+There are only 3 levels of heading in gemtext
+### This is the last level
+Lists:
+* one
+* two
+* three
+```
+
+There is however a fundamental difference in how lines are parsed: in gemtext,
+newlines in the code are preserved. This sounds completely normal for anyone
+used to modern word processors, but it is different from how html, markdown
+and Latex work, just to name a few. In practice, this means that in gemtext
+you nhave to write your paragraphs as long lines, without inserting line breaks
+unless you want the line to be broken at that specific point.
+This may be annoying for people used to old-style line-based editors, such as
+vi, but it makes parsing a gemtext file much simpler.
+
+There are only three other things you can do in gemtext: links, block quotes
+and preformatted text.
+
+Links consist of a single line starting with `=>`, followed by a link and
+(optionally) by the text you want to appear instead of the URL of the link.
+
+```
+=> gemini://tronto.net A link to my homepage
+```
+
+Blockquotes are simply lines starting with `>`:
+
+```
+> This is a quote
+```
+
+Finally, preformatted text is any text between two lines consisting of three
+backticks. It is going to appear as it is when rendered, i.e. your browser
+won't parse any gemtext syntax inside preformatted text.
+
+````
+```
+This is preformatted text
+It can be useful to display ASCII art, like this
+ /\_/\
+( o.o )
+ > ^ <
+=> This line will not be interpreted as a link
+```
+````
+
+And that's it, you now know gemtext. There is no inline formatting, no
+embedded media, no CSS - your browser will take care of the styling and
+if you want to view a picture you can just download it and open it with
+an external app.
+
+## Gemini in practice
+
+Gemini is basically a very stripped down version of the Internet. To me it
+feels like some kind of very nice, underground web. Some *capsules* I like
+browsing are [smol.pub](gemini://smol.pub) and
+[midnight.pub](gemini://midnight.pub). I don't have an account there
+yet, but I think I will make one at some point. I also check the
+[Antenna feed aggregator](gemini://warmedal.se/~antenna) to discover new
+stuff.
+
+Basically, if you like the idea of a small and text-only version
+of the internet, you should check out the gemini space.
+The page [geminiquickst.art](https://geminiquickst.art) suggests some
+browsers - I personally use gmnln, but it is more or less an interactive
+curl, you probably won't like it.
+
+## Conclusions
+
+I think gemini is an interesting exercise of minimalism, which I like.
+I am not a networking expert, so I don't know what the pros and cons of using
+gemini:// rather than http(s):// are, but I quite like gemtext as a markup
+language. I am not too fond of using long lines, because as a terminal editor
+user I am used to breaking up lines at 70-80 characters, but this is not
+a deal-breaker. However, I still prefer making use of a few of the extra
+features that html offers, such as inline formatting.
+
+I will keep offering this website in gemtext via gemini://, but it will
+stay html-first. This means that inline links will look a bit ugly in gemini
+and, more annoyingly for the few gemini users, I am always going to use
+http(s) links even when a gemini counterpart is available.
+
diff --git a/src/blog/blog.md b/src/blog/blog.md
@@ -2,5 +2,6 @@
[RSS Feed](feed.xml)
+* 2022-06-04 [The gemini protocol](2022-06-04-gemini)
* 2022-05-29 [The man page reading club: man(1)](2022-05-29-man)
* 2022-05-21 [Blogs](2022-05-21-blogs)
diff --git a/src/blog/feed.xml b/src/blog/feed.xml
@@ -9,6 +9,13 @@ Thoughts about software, computers and whatever I feel like sharing
</description>
<item>
+<title>The gemini protocol</title>
+<link>https://sebastiano.tronto.net/blog/2022-06-04-gemini</link>
+<description>The gemini protocol</description>
+<pubDate>2022-06-04</pubDate>
+</item>
+
+<item>
<title>The man page reading club: man(1)</title>
<link>https://sebastiano.tronto.net/blog/2022-05-29-man</link>
<description>The man page reading club: man(1)</description>
