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Spaceship Exim

Volume 3, Issue 43; 02 Dec 2019

Detecting unsent email.

This is a quick little hack, probably only useful to me, but perhaps it’ll inspire you to do something useful for you.

I use Exim to send email. (My email configuration is…complicated.) By “use exim”, I mean that I’ve configured Emacs to use Exim.

(setq sendmail-program "/usr/local/bin/exim")

It’s not really integrated into whatever MacOS does to track successfully or unsuccessfully sent messages.

Here’s what I’m looking at today:

$ exim -bp
54h  1.5K Q1QJV5-00207L-QY <ndw@nwalsh.com>
        D someuser@example.org
          someotheruser@example.org

My attempt to send email to someotheruser@example.org failed 54 hours ago. On closer inspection, this message was supposed to go to three addresses and I mangled some punctuation in the headers.

I simply don’t remember to check the queue very often so I’ve sometimes found messages days or weeks old in there. Embarrassing. I could make it visible when I reboot or when I start a new shell, but those things don’t necessarily happen often either. (New shells probably do, in fact, but nevermind.)

I’ve got one of those fancy prompt configurations installed, so my shell prompt provides a bunch of useful information. Here’s a slightly silly example:

ndw on  master [⇡!?] via ⬢ v8.15.1 on 🐳 v19.03.5 via 🐍 3.7.4
$

That’s my prompt when I’m in my home directory (ndw), which is checked out of git ( master),The character in front of “master” is &#xe0a0;. It displays as the “code-fork” icon for me. I’m not sure what font it’s coming from; it’s rendered in Font Awesome slightly differently, but that link will give you a sense of the icon. Unfortunately, U+E0A0 is in the Unicode private use area and unlikely to be displayed correctly in your browser. It looks fine for me in Emacs and the shell. is ahead of the remote branch (), and has both changed (!) and untracked files (?). I created a package.json file, so it’s telling me that will use Node v8.15.1; there’s a docker-compose.yml file, so it’s telling me that will use Docker v19.03.5; and I created foo.py, so it’s telling me that will use Python version 3.7.4.

Obviously the thing to do is add an annotation to the prompt if there are unsent messages in the Exim queue!

Luckily, it was straightforward to hack together from the Spaceship API example:

#
# Exim
#
# Exim will display &#x1f4eb; in the prompt if exim reports
# that there is unsent mail.

# ------------------------------------------------------------------------------
# Configuration
# ------------------------------------------------------------------------------

SPACESHIP_EXIM_SHOW="${SPACESHIP_EXIM_SHOW=true}"
SPACESHIP_EXIM_PREFIX=""
SPACESHIP_EXIM_SUFFIX=" "
SPACESHIP_EXIM_COLOR="${SPACESHIP_EXIM_COLOR="white"}"
SPACESHIP_EXIM_CHAR="📫"

# ------------------------------------------------------------------------------
# Section
# ------------------------------------------------------------------------------

# Show exim status
spaceship_exim() {
  # If SPACESHIP_EXIM_SHOW is false, don't show exim section
  [[ $SPACESHIP_EXIM_SHOW == false ]] && return

  # Check if exim command is available for execution
  spaceship::exists exim || return

  # Show exim section only when there is unsent mail
  [[ `exim -bp | wc -l` -gt 0 ]] || return

  # Display exim section
  spaceship::section \
    "$SPACESHIP_EXIM_COLOR" \
    "$SPACESHIP_EXIM_PREFIX" \
    "$SPACESHIP_EXIM_CHAR" \
    "$SPACESHIP_EXIM_SUFFIX"
}

I source that at the end of my ~/.zshrc file and add exim to SPACESHIP_PROMPT_ORDER just before the line separator and now my prompt is:

ndw on  master [⇡?] on 🐳 v19.03.5 📫
$

(It’s slightly more reasonable because I deleted the package.json and foo.py files.)

Sweet. Well, except for the busted message I have to resend. But at least I know there is a busted message now!

Share and enjoy!

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