Ellipsis Directory

A quick hack to insert .. into long paths for easy viewing in my terminal.

Why Lua?

I don't know much about it but wanted to learn a little more.

Dependencies

• luafilesystem (luarocks luafilesystem)

Usage

ellipsis_directory.lua <depth>

Installation / Example

Running ellipsis_directory.lua will transform your path from something like ~/Documents/Shared/Scripts/Projects/website/html/photos to a shorter path: ~/Documents/Shared/../../../html/photos

For this to work, it is necessary to reset your PS1 environment variable each time a command executes in your terminal. This can be done in a few steps:

• Determine the depth at which you would like have your path shortened.
  • In this example, I am using a depth of 4
• Create a function to update your PS1. This will be execututed with PROMPT_COMMAND

function ellipsis_directory_reload() {
  export PS1+="$(ellipsis_directory.lua 4)"
}

• Finally, add this function to your PROMPT_COMMAND environment variable

PROMPT_COMMAND=ellipsis_directory_reload

After sourcing your bash profile (or whever your PS1 variable is stored), the path should look like the following:

~/Documents/Shared/../../../html/photos

Caveats / Warning

Depending how your environment is set up you may need to include your entire PS1 variable in the ellipsis_directory_reload() command. A live example from my bash environment file:

nozero() { date +%r | sed 's/\:[0-9]*//2;s/^0//g'; }
yazero() { date +%r | sed 's/\:[0-9]*//2'; }

_ellipsis_directory() {
  # insert the time
  export PS1='\n$(if [[ $(date +%r) =~ ^0 ]]; then nozero; else yazero; fi)'

  # colorize and add open square bracket
  export PS1+=" \[\e[31m\][\[\e[m\]\[\e[31m\]"

  # add the directory via ellipsis_directory, shortening at a depth of 4
  export PS1+="$(${HOME}/Documents/Shared/Dotfiles/elipsis_directory_lua/ed.lua 4)"

  # insert a closing square bracket, add a new line and arrow
  export PS1+="\[\e[m\]\[\e[31m\]]\[\e[m\] \n-> "
}

# finally, add the function to PROMPT_COMMAND
export PROMPT_COMMAND=_ellipsis_directory

• The above produces the following bash prompt

Note

an observant reader will notice that .. is not actually an ellipsis.