iTerm Profiles

2019-02-24

Hacking on iTerm 2

I wanted a small weekend project to hack on today, so I decided to hack a little on iTerm. First, I wanted to make it easier to switch between light and dark profiles. Switching profiles in iTerm requires a bunch of clicks, and I hate using my mouse.

So, I set out to build a few features: - A bash function to switch between light and dark profiles - Automatically select a specific profile when I connect to a remote server - Randomly select a profile when opening a new tab (to more visual context for different mental context)

Granted - this isn't for everyone. Many people find backgrounds in their terminal to be distracting, and use their prompt to make these distinctions. But, I love having background images and the more visual cues, the better.

Control iTerm Profiles from bash

iTerm has a special escape sequence it can catch to switch profiles:

echo -e "\033]50;SetProfile=MyAwesomeProfile\a"

iTerm also sets an environmental variable, ITERM_PROFILE, but running the above doesn't update it. So here is a simple bash function to change the current iTerm session's profile:

function iterm-profile() {
  echo -e "\033]50;SetProfile=$1\a"
  ITERM_PROFILE=$1
}

Switching between light and dark

iTerm doesn't have an easy way to change settings of a profile, so to accomplish this I just created a light and dark version of all my profiles, i.e. Dark-1 and Light-1. Assuming that the current profile has a respective opposite version, here's a function to switch between the two:

function flip-iterm-profile() {
  iterm-profile $(
  python -c '
import sys
dl, profile = sys.argv[1].split("-")
dl = {"Dark": "Light", "Light": "Dark"}[dl]
print(dl+"-"+profile)
  ' $ITERM_PROFILE)
}

Change Profile for remote connection

I use Eternal Terminal for my remote connections. It keeps your connection alive, between network changes (similar to Mosh), but also allows for port forwarding, which I use with sshx in my emacs session. One downside of Eternal Terminal, though, is that it won't read LocalForward settings from your ssh config. I also have it connect directly to my already running tmux session on my remote session. This ends up in a fairly complicated connection command, which I had aliased:

alias up='et -c="tmux a" -x -t="10022:22" devserver'

To add in the profile changing, I created two profiles, Dark-Devserver and Light-Devserver, and I changed the alias to a function:

function up() {
  PREVIOUS_PROFILE=$ITERM_PROFILE
  iterm-profile $(
  python -c '
import sys
dl, profile = sys.argv[1].split("-")
print(dl+"-Devserver")
  ' $ITERM_PROFILE)
  et -c="tmux a" -x -t="10022:22" devserver.et:8080
  iterm-profile $PREVIOUS_PROFILE
}

The et command could easily be swapped for a ssh or mosh command. The only extra piece here is that I maintain the dark/light setting from the existing profile.

This can also be accomplished with Automatic Profile Switching in iTerm, but it wouldn't maintain the light/dark setting. You could also include similar code in your bash profile on the server, but that was complicated by my connecting directly to a running tmux session.

Random Profile on Launch

This one only works because I created six pairs of profiles named Light-<n> and Dark-<n>. I then (somewhat arbitrarily) decided to set the profile to Light between 6am and 3pm, and Dark otherwise. Additionally, a random choice doesn't guarantee a unique profile, but it's simple enough to call the function again if you're unsatisfied.

function random-iterm-profile() {
  # pick random profile (of the 6)
  # Light between 6am and 3pm, otherwise Dark
  iterm-profile $(
  python -c '
import random
from datetime import datetime
dl = "Light" if 6 < datetime.now().hour < 15 else "Dark"
profile = str(random.randint(1,6))
print(dl+"-"+profile)')
}

Here's what it looks like calling it a few times:

Wrap it all up

If you want to copy and paste directly in your bash profile, here you go. You'll need the following iTerm profiles defined:

Light-1
Light-2
Light-3
Light-4
Light-5
Light-6
Light-Devserver
Dark-1
Dark-2
Dark-3
Dark-4
Dark-5
Dark-6
Dark-Devserver

and you'll need to change the et command to something that makes sense for you.

function up() {
  PREVIOUS_PROFILE=$ITERM_PROFILE
  iterm-profile $(
  python -c '
import sys
dl, profile = sys.argv[1].split("-")
print(dl+"-Devserver")
  ' $ITERM_PROFILE)
  et -c="tmux a" -x -t="10022:22" devserver
  iterm-profile $PREVIOUS_PROFILE
}

function iterm-profile() {
  echo -e "\033]50;SetProfile=$1\a"
  ITERM_PROFILE=$1
}

function flip-iterm-profile() {
  iterm-profile $(
  python -c '
import sys
dl, profile = sys.argv[1].split("-")
dl = {"Dark": "Light", "Light": "Dark"}[dl]
print(dl+"-"+profile)
  ' $ITERM_PROFILE)
}

function random-iterm-profile() {
  # pick random profile (of the 6)
  # Light between 6am and 3pm, otherwise Dark
  iterm-profile $(
  python -c '
import random
from datetime import datetime
dl = "Light" if 6 < datetime.now().hour < 15 else "Dark"
profile = str(random.randint(1,6))
print(dl+"-"+profile)')
}

random-iterm-profile