#! /bin/sh

# growing -- watch the growth rate of given files 
# $Id: growing,v 1.1 1998/09/06 16:46:33 cdua Exp cdua $
# Carlos Duarte, 970911

temp=/tmp/a1QsW.$$.OiJ
trap 'rm -f $temp; exit 0' SIGINT

delay=10

USAGE="\
usage: $0 [-h] [-d delay] files...

  -h      this help
  -d delay
	  use delay seconds. if not specified, defaults to $delay

examples: 
    gzip -9c big > big.gz& compress -c big > big.Z& $0 -d 2 big.*
"

while : ; do
	case x"$1" in 
	x-h)	echo "$USAGE"; exit 1 ;;
	x-d)	shift; 
		delay=`echo $1 | awk '
		{if (NF>=1) x=$1+0; if (x==0) x='$delay'
		print x}'`
		;;
	x--)	shift; break ;;
	x-?)	echo "invalid option -- `echo $1|cut -c2-`"
		echo "$USAGE"; exit 1 ;;
	*)	break ;;
	esac
	shift
done

# if _must_ accept one extra argument after options
if test $# -eq 0; then echo "$USAGE"; exit 1; fi

echo 0 > $temp
wc -c /dev/null "$@" | sed '1d; s/\([0-9][0-9]*\).*/& \1/; $d' >> $temp

while :; do
	sleep $delay
	wc -c /dev/null "$@" | sed -e 1d -e \$d | awk '
	BEGIN {
		delay='"$delay"'
		tmp="'"$temp"'"
		getline < tmp
		total = $1 + delay
		i=0
		while ((getline < tmp)) {
			o_cur[++i] = $1
			o_tot[i] = $3
		}
		close(tmp); 
		print total > tmp
		i=0; 
	}

	{
		cur_rate = ($1 - o_cur[++i])/delay/1000;  
		tot_rate = ($1 - o_tot[i])/total/1000;  
		fmt = $2 ":                  "
		printf "%.12s %3d [currently: %3d] KB/sec\n", 
				fmt, 
				tot_rate,
				cur_rate 
		print $0, o_tot[i] > tmp 
	}

	END {
		close (tmp)
	}'
done