A speaking clock with a configurable reporting frequency

clock-speak

#!/bin/bash

USAGE="$0 [TIMESPEC]
A speaking clock that says the time once every TIMESPEC.
For example, \"$0 1 hour\" would speak at the boundary of every hour,
while \"$0 15 minutes\" would speak four times as often.
In technical terms, the time is reported when time since epoch is divisible by TIMESPEC.
TIMESPEC defaults to 1 hour.
"

# set this to empty string to disable special case "o'clock" behaviour
OCLOCK=${OCLOCK:-true}

# change this to your favourite text-to-speech application
SPEAK="espeak"

if [ "$#" -lt 1 ]; then
	timespec=3600
else
	timespec=$((`date +%s -d "$*"` - `date +%s`))
fi

if [ ! "$timespec" ] || [ "$timespec" -lt 0 ]; then
	echo "Error interpreting timespec"
	exit 1
fi

while true; do
	timeleft=$((timespec - (`date +%s` % timespec)))
	sleep "$timeleft" || exit # in case of bad screwup causing an inf loop
	if [ -n "$OCLOCK" ] && [ "`date +%M`" == "00" ]; then
		date +"%-H o clock" | $SPEAK
	else
		date +"%-H %-M" | $SPEAK
	fi
done