OSX Command Alerts - send OSX notifications when long running commands complete requires terminal-notifier: https://github.com/alloy/terminal-notifier

command_alert.bash

#!/bin/bash
#
# OSX Command Alerts - notify when long running commands complete
#
# Uses preexec/precmd hooks by Glyph Lefkowitz
#     - original: http://glyf.livejournal.com/63106.html
#     - also here: https://twistedmatrix.com/users/glyph/preexec.bash.txt
#
# Define what constitutes long running (seconds)
export NOTIFY_DURATION=10
#
# ---------- BEGIN SETUP FOR PREEXEC HOOKS ---------- #
# This variable describes whether we are currently in "interactive mode";
# i.e. whether this shell has just executed a prompt and is waiting for user
# input.  It documents whether the current command invoked by the trace hook is
# run interactively by the user; it's set immediately after the prompt hook,
# and unset as soon as the trace hook is run.
preexec_interactive_mode=""

# This function is installed as the PROMPT_COMMAND; it is invoked before each
# interactive prompt display.  It sets a variable to indicate that the prompt
# was just displayed, to allow the DEBUG trap, below, to know that the next
# command is likely interactive.
function preexec_invoke_cmd () {
    precmd
    preexec_interactive_mode="yes"
}

# This function is installed as the DEBUG trap.  It is invoked before each
# interactive prompt display.  Its purpose is to inspect the current
# environment to attempt to detect if the current command is being invoked
# interactively, and invoke 'preexec' if so.
function preexec_invoke_exec () {
    if [[ -n "$COMP_LINE" ]]
    then
        # We're in the middle of a completer.  This obviously can't be
        # an interactively issued command.
        return
    fi
    if [[ -z "$preexec_interactive_mode" ]]
    then
        # We're doing something related to displaying the prompt.  Let the
        # prompt set the title instead of me.
        return
    else
        # If we're in a subshell, then the prompt won't be re-displayed to put
        # us back into interactive mode, so let's not set the variable back.
        # In other words, if you have a subshell like
        #   (sleep 1; sleep 2)
        # You want to see the 'sleep 2' as a set_command_title as well.
        if [[ 0 -eq "$BASH_SUBSHELL" ]]
        then
            preexec_interactive_mode=""
        fi
    fi
    if [[ "preexec_invoke_cmd" == "$BASH_COMMAND" ]]
    then
        # Sadly, there's no cleaner way to detect two prompts being displayed
        # one after another.  This makes it important that PROMPT_COMMAND
        # remain set _exactly_ as below in preexec_install.  Let's switch back
        # out of interactive mode and not trace any of the commands run in
        # precmd.

        # Given their buggy interaction between BASH_COMMAND and debug traps,
        # versions of bash prior to 3.1 can't detect this at all.
        preexec_interactive_mode=""
        return
    fi

    # In more recent versions of bash, this could be set via the "BASH_COMMAND"
    # variable, but using history here is better in some ways: for example, "ps
    # auxf | less" will show up with both sides of the pipe if we use history,
    # but only as "ps auxf" if not.
    local this_command=`history 1 | sed -e "s/^[ ]*[0-9]*[ ]*//g"`;

    # If none of the previous checks have earlied out of this function, then
    # the command is in fact interactive and we should invoke the user's
    # preexec hook with the running command as an argument.
    preexec "$this_command"
}

# Execute this to set up preexec and precmd execution.
function preexec_install () {

    # *BOTH* of these options need to be set for the DEBUG trap to be invoked
    # in ( ) subshells.  This smells like a bug in bash to me.  The null stderr
    # redirections are to quiet errors on bash2.05 (i.e. OSX's default shell)
    # where the options can't be set, and it's impossible to inherit the trap
    # into subshells.

    set -o functrace > /dev/null 2>&1
    shopt -s extdebug > /dev/null 2>&1

    # Finally, install the actual traps.
    old_prompt_command=`echo "$PROMPT_COMMAND" | sed 's/ $//' | sed 's/;$//'`
    PROMPT_COMMAND="${old_prompt_command};preexec_invoke_cmd"
    trap 'preexec_invoke_exec' DEBUG
}

# ---------- BEGIN SETUP FOR NOTIFICATIONS ---------- #
function get_time () {
    date +"%s"
}

function last_command () {
    history 1 | sed 's/^ *[0-9]* *//'
}

function preexec () {
    cmd_start=$(get_time)
}

function precmd () {
    cmd_end=$(get_time)
    
    if [[ -n "$cmd_start" ]]
    then
        cmd_duration=`expr $cmd_end - $cmd_start`

        if [[ "$cmd_duration" -gt "$NOTIFY_DURATION" ]]
        then 
            terminal-notifier -message "Command complete: $(last_command)"
        fi
    fi
}

# ---------- INSTALL PREEXEC HOOKS ---------- #
preexec_install