Show notifications in your terminal

show_notifications.bash

# All my gist code is licensed under the terms of the MIT license.

# Video demo: https://www.youtube.com/shorts/WVyqVkGYb4k

# Add this somewhere in ~/.bashrc

# write_message
# - write a message on the lower right corner of the terminal
function write_message () {
  if [[ "$#" -eq 0 ]]; then
    echo "write_message: please provide a message"
    return
  fi

  local message="  ${*}  "

  # CSI sequences
  local csi="\033["
  local save_cursor_position="${csi}s"
  local restore_cursor_position="${csi}u"
  local erase_from_cursor_to_end_of_screen="${csi}J"
  local reset="${csi}0m"
  local set_bg_color="${csi}44m"
  local set_fg_color="${csi}30m"
  local move_cursor_to_bottom="${csi}${LINES};$((COLUMNS - ${#message}))H"

  # write the message
  printf "${save_cursor_position}"
  printf "${move_cursor_to_bottom}"
  printf "${set_bg_color}${set_fg_color}${message}${reset}"
  printf "${restore_cursor_position}"

  # clean up after 5 seconds of timeout
  function __clean_up () {
    sleep 5
    printf "${save_cursor_position}"
    printf "${move_cursor_to_bottom}"
    printf "${erase_from_cursor_to_end_of_screen}"
    printf "${restore_cursor_position}"
  }

  # clean up in the background
  # run in a subshell to avoid showing 'job control' output
  (__clean_up &)

  # clean up internal functions
  unset -f __clean_up
}

# sample function
# run this in the background with 'check_email &'
function check_email () {
  sleep 10
  write_message "You have 69 new emails (total 420 unread)"
}

@Stewie410 Thanks a lot! I updated the code with your feedback.

A few notes:

• I believe $message should be redefined in __write because __write doesn't always print the message passed to write_message: It also prints an empty message of the same length to clean up.
• I like the function keyword.
• I also like the local keyword on the same line as the definition.
• I personally don't like tput for a few reasons:
  • I think it's a historical accident from the pre-xterm days. Now that terminal emulator compatibility is better, there's no need to avoid writing escape sequences by hand. I would take a tput like library with extremely explicit names, but I don't think that exists right now, and in any case, variables are good enough for documenting.
  • It starts a new process just for writing strings (this is hypocritical of me because I don't mind having 5 consecutive printfs, but we are all sinners under the shadow of our lord Jesus Christ).

Thanks again. I'm about to make a small improvement to optionally render a link that you can either click or open with a keybinding. It's surprisingly easy to do, and I wonder why no more people are exploiting these terminal shenanigans for custom hacks.

Edit: I simplified a bit more and managed to remove one internal function.

I did not have luck running this, the popup appears for 0.1s and disappears, Love the idea, but couldn't fix it.