#!/bin/bash

# Requires inofity-tools.

# Get filename to watch.
if [[ -z "$1" ]]
then
	cat << EOM
Usage: $(basename $0) <filename> [-c <context>] [args to 'notify-send' ...]
EOM
	exit 1
fi

fname="$1"
shift

# Lines of context?
context=10
if [[ "$1" == "-c" ]]
then
	context="$2"
	shift
	shift
fi

# Make sure it exists.
if [[ ! -f "$fname" ]]
then
	touch "$fname" || exit 1
fi

# Enter the watch loop.
while inotifywait -q -q -e close_write "$fname"
do
	notify-send "$@" "$(tail -n "$context" "$fname" | tac)"
done

notify-send "$@" "Error: Can no longer watch \`$fname'!"