promptly

Get a prompt, promptly.

What is this?

Windows is astonishingly slow at spawning new processes. Older raspberry pis are just slow in general. If you are used to having a complex, useful prompt on your laptops and desktops, it can take up to seconds for the same prompt to render when you log into one of these slower platforms. Rather than accept a less useful or uglier prompt, I decided to move my prompt into a faster language. On a fast desktop running Linux, promptly takes ~5ms to render a prompt. On a fast desktop running windows, promptly takes about 20ms to render the same prompt. This is a marked improvement over the 0.1s and 1.5s, respectively, that the bash equivalent takes to execute.

Installation

1. I've not yet had enough demand to ship binary packages, so to install you'll need Rust. Go to rustup.rs and install Rust version 1.17 or greater by following the easy, on-screen directions.
2. Then, in the project directory, do cargo install. If there are red lines, please file an issue!
3. Run promptly --status 0 --time 0 --width 80 --no-readline to make sure it's working. If things don't appear to be rendering properly in your terminal, adjust the command line and fonts until things look as awesome as desired. You can run promptly --help to see the available rendering options.
4. Finally, install promptly as your prompt command -

Bash

# Add cargo's bin dir to path.
export PATH="${PATH}:${HOME}/.cargo/bin"

# Bash has a builtin timer that you can use to time process execution at second resolution.
function timer_start {
  timer=${timer:-$SECONDS}
}
function timer_stop {
  TIMER_OUT=$(($SECONDS - $timer))
  unset timer
}

# We have to wrap promptly in a sub-command to capture the status code.
function doprompt {
  STATUS_OUT=$?
  timer_stop
  export PS1=$(promptly --status ${STATUS_OUT} --width ${COLUMNS} --time ${TIMER_OUT})
}

trap 'timer_start' DEBUG
export PROMPT_COMMAND=doprompt

Zsh

# Add cargo's bin dir to path.
export PATH="${PATH}:${HOME}/.cargo/bin"

function timer_start {
  timer=${timer:-$SECONDS}
}
function timer_stop {
  if [ $timer ]; then
    TIMER_OUT=$(($SECONDS - $timer))
    unset timer
  else
    TIMER_OUT=0
  fi
}

# We have to wrap promptly in a sub-command to capture the status code.
function doprompt {
  STATUS_OUT=$?
  timer_stop
  export PS1=$(promptly --no-readline --status ${STATUS_OUT} --width ${COLUMNS} --time ${TIMER_OUT})
}

preexec_functions+=(timer_start)
precmd_functions+=(doprompt)

Other shells

Consult your shell's documentation and please file a PR with the instructions once you get it working.