macOS notification and terminal bell on completion of long running zsh process

znote.sh

#!/usr/bin/env zsh

# This script prints a bell character and displays a notification when a command finishes
# if it has been running for longer than $zbell_duration seconds.
# If there are programs that you know run long that you don't
# want to bell after, then add them to $zbell_ignore.
#
# It requires the terminal-notifier ruby gem (gem install terminal-notifier)
#
# Written by Jean-Philippe Ouellet <jpo@vt.edu>
# Made available under the ISC license.
#
# Some modifications by Christopher Owen <mail@christopherowen.id.au>

# only do this if we're in an interactive shell
[[ -o interactive ]] || return

# get $EPOCHSECONDS. builtins are faster than date(1)
zmodload zsh/datetime || return

# make sure we can register hooks
autoload -Uz add-zsh-hook || return

# initialize zbell_duration if not set
(( ${+zbell_duration} )) || zbell_duration=15

# initialize zbell_ignore if not set
(( ${+zbell_ignore} )) || zbell_ignore=($EDITOR $PAGER ping)

# initialize it because otherwise we compare a date and an empty string
# the first time we see the prompt. it's fine to have lastcmd empty on the
# initial run because it evaluates to an empty string, and splitting an
# empty string just results in an empty array.
zbell_timestamp=$EPOCHSECONDS

# right before we begin to execute something, store the time it started at
zbell_begin() {
	zbell_timestamp=$EPOCHSECONDS
	zbell_lastcmd=$1
}

# when it finishes, if it's been running longer than $zbell_duration,
# and we dont have an ignored command in the line, then print a bell.
zbell_end() {
	proc_stat="$?"

	has_ignored_cmd=0

	if [[ $proc_stat = "130" ]]; then
	    has_ignored_cmd=1
	fi

	elapsed_time=$(( $EPOCHSECONDS - $zbell_timestamp ))

	ran_long=$(( $elapsed_time >= $zbell_duration ))

	for cmd in ${(s:;:)zbell_lastcmd//|/;}; do
		words=(${(z)cmd})
		util=${words[1]}
		if (( ${zbell_ignore[(i)$util]} <= ${#zbell_ignore} )); then
			has_ignored_cmd=1
			break
		fi
	done

	if (( ! $has_ignored_cmd )) && (( ran_long )); then
	    display_elapsed=$(date -u -r ${elapsed_time} +%T)
	    terminal-notifier -title znote -activate com.apple.terminal -group "$TERM_SESSION_ID" -message "${util} completed (⏱ ${display_elapsed})"
	    print -n "\a"
	fi
}

# register the functions as hooks
add-zsh-hook preexec zbell_begin
add-zsh-hook precmd zbell_end