#!/bin/sh
# I haven't seen yet how random this really is.
LINES=`cat $1|wc -l`
SEED=`date +%s`
# Use this for any-time randomness.
#FUNC=`date +%m%S`
# Use this for once-a-day randomness.
FUNC=`date +%w%d%W`
# debug
#echo $SEED $FUNC $LINES
RANDLINE=`expr $SEED % $FUNC % $LINES`
head -$RANDLINE $1 |tail -1