tellme: A simple wrapper to execute commands and provide notification of the results

tellme.sh

#!/bin/bash

# Executes the provided command and provides notification when execution has
# completed
#
# Usage: tellme <cmd>
#
# Examples:
#
#   tellme ./pants compile science::
#   tellme curl http://example.com/giant_file
#
# Settings are controlled by environment variables (instead of flags) to
# simplify running the provided command.
#
# Control which forms of notification you want by setting the environment
# variables TELLME_SUCCESS and TELLME_FAILURE to a comma-separated list of the
# following values:
#
# - bell: output the bell character (^G) in the terminal
# - beep: play the system alert sound
# - notification_center: show a message in OS X's Notification Center
# - play: play the sound file at the provided path (play /foo/bar/baz.wav), or
#     play a random file in the provided directory. The file must be a format
#     supported by `afplay`.
# - say: use the `say` command to speak the subsequent string
#
# Examples:
#
#   TELLME_SUCCESS="say Command exited successfully,play $HOME/crowd_cheering.wav"
#   TELLME_SUCCESS="notification_center,play --volume 0.25 $HOME/nbajam_heating_up.wav"
#   TELLME_FAILURE="beep,say,notification_center"
#   TELLME_FAILURE="say --voice Cellos What you started has ended in failure"
#
# If you configure your defaults in a shell file (.bashrc, .zshrc) remember to
# export the values:
#
#   export TELLME_SUCCESS="..."

tellme_success=${TELLME_SUCCESS-say Success,notification_center}
tellme_failure=${TELLME_FAILURE-beep,say Failure,notification_center}
default_success_msg=Success
default_failure_msg=Failure

## ACTION HANDLERS ##########################################################

#  Runs the provided command using `afplay`. This function assumes that the
#  last argument is a file name or directory. If it is a directory, a random
#  file is selected from within that directory.
function background_play() {
  local cmd=("$@")
  # OS X uses an old version of bash which does not support cmd[-1]
  # See http://unix.stackexchange.com/questions/198787
  local file="${cmd[${#cmd[@]}-1]}"

  if [[ -d $file ]]; then
    unset cmd[${#cmd[@]}-1]
    cmd+=($(random_file $file))
  fi

  (afplay "${cmd[@]}" &)
}

function background_say() {
  (say $@ >/dev/null 2>&1 &)
}

function beep() {
  osascript -e "beep 1"
}

function bell() {
  tput bel
}

function notification_center() {
  local title=$1
  local msg=${@:2}

  osascript -e "display notification \"$msg\" with title \"$title\""
}

## HELPERS ##################################################################

function strip() {
  local to_strip=$1
  echo "${@:2}" | sed "s/$to_strip[ =]//"
}

# Select a random file from the specified directory
function random_file() {
  local dir=$1
  files=($dir/*)
  local num_files=${#files[@]}

  # See http://stackoverflow.com/questions/2388488
  RANDOM=$$$(date +%s)
  selected_file=${files[$RANDOM % $num_files]}
  echo $selected_file
}

## "main" ###################################################################

# Run the provided command
cmd="$@"
"$@"
result=$?
escaped_cmd=$(echo $cmd | sed 's/\"/\\"/g')

# Select actions based on success or failure
if [[ $result -eq 0 ]]; then
  actions=$(echo $tellme_success | sed -E "s/say(,)|say$/say $default_success_msg\1/")
else
  actions=$(echo $tellme_failure | sed -E "s/say(,)|say$/say $default_failure_msg\1/")
fi

# Process actions
echo $actions | tr ',' '\n' | while read action; do

  case "$action" in
    say*)
      background_say $(strip say $action)
      ;;
    notification_center*)
      notification_center "Command result" $escaped_cmd
      ;;
    bell*)
      bell
      ;;
    beep*)
      beep
      ;;
    play*)
      background_play $(strip play $action)
      ;;
  esac

done

exit $result