120 lines
3.8 KiB
Markdown
120 lines
3.8 KiB
Markdown
title: Emacs server the fun way
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---
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pub_date: 2020-04-23
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---
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author: Nico Schottelius
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---
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twitter_handle: NicoSchottelius
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---
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_hidden: no
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---
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_discoverable: yes
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---
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abstract:
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Let's dive into a very nice emacs feature
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---
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body:
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Today I want to talk about how amazing emacs is. Not because it is the
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most feature complete operating system out there or because
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[it fully emulates vi/vim](https://github.com/emacs-evil/evil).
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No, because emacs has a very nice feature called **emacs server**.
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## What's an emacs server?
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If emacs is not an operating system, at least emacs stands for
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"**e**ight **m**egabytes **a**nd **c**onstantly **s**wapping", doesn't
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it? (This is actually from times where 8 megabytes were quite a lot of
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memory)
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So why do people make fun of emacs and how is it related to the emacs
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server?
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Emacs, like any other operating system, loads a lot of things at
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startup. In my case this is initialising
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[org-mode](https://orgmode.org/), starting my mail client, calculating
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my agenda view to tell me what to do today.
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An emacs server creates a special emacs process that listens on a
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socket for connecting to it. This way the initialisation is already
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done before you connect to it and all
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configurations are already loaded. This is the actual "slow" part of
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emacs. And is a bit similar to starting python, which also needs to
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load its libraries at start.
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With the emacs server running, you can connect to it using the
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**emacsclient** program.
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As a matter of fact,
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[rxvt-unicode](http://software.schmorp.de/pkg/rxvt-unicode.html) also
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knows about a server mode (checkout the manpage, look for
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**urxvtd -q -f -o**). For rxvt-unicode, you'd use **urxvtc** to
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connect to it. So quite simlar.
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## What is so cool about the emacs server?
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Saving a lot of response time and making working with emacs **feel**
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much faster is the obvious advantage. However, there is a much bigger
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one:
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With the emacs server, you can connect to it from the terminal **and** X
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Windows. Because the emacs server also manages the buffers ("open
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files" for non-emacs users), you can view the same open file from the
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terminal or an x window.
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## Turning the notebook into a server
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As you might now, we at ungleich are pretty much into IPv6. So all of
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our devices are generally speaking world-wide reachable. Our work
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notebooks are no exception from that. In fact, most notebooks even
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have their own [/48 IPv6 network assigned via
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VPN](/u/products/ipv6-vpn/).
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So if I am away from my notebook, but need to check my open (and
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potentially unsaved) notes or view my emails, I can use any other
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computer, ssh to my notebook and type **emacslient -nw** in the
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terminal.
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While my regular emacs is running as an X11 window, I can select,
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display and work in all buffers that I have previously opened in the
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emacs server. In the terminal, on a remote computer.
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## How to configure your system to use the emacs server
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In my case I start the emacs server when I start X11 in my .xinitrc:
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```
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eval $(ssh-agent)
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...
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urxvtd -q -f -o
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emacs --daemon
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...
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```
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Instead of running emacs --daemon, you can also use **M-x
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server-start** in a running emacs process.
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And because I always want to have my mail client open, just after I start
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i3, I have i3 launch the following command:
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```
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ssh-add </dev/null && emacsclient -c -e '(mu4e)'
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```
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The connection to my mailserver is tunneled via SSH to prevent
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security issues from using SSL/TLS. Thus I need to add all my ssh keys
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to the ssh-agent, before starting my mail client.
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To actually open a new emacs windown (aka "frame" in emacs speech), I
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use the following configuration in my **~/.i3/config**:
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```
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bindsym $mod+Tab exec emacsclient -c
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```
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## How does this look like?
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Below you find a screenshot of my writing this article. The upper
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window is the X11 window, the lower window is a terminal window (they
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happen to be configured to have the same nice background colour).
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