: The top twenty shell.  Keeps a .cache of the top twenty commands
: The cache maintains an order most likely to represent the frequency of use.
: and presents them as a menu to the user
N=20
NMINUS1=`expr $N - 1`
if [ $# -eq 0 ]
then prompt=`hostname`':Select command? '
else echo Usage: $0 ; exit 1
fi
for server in blaze iris orion scorpio gemini challenge indigo
do	xhost $server >/dev/null 2>/dev/null & 
done
echo Input CTRL/D to exit
if [ -r $HOME/.cache ]
then
	cat -n $HOME/.cache
else
	cat /dev/null >$HOME/.cache
fi
echo Input command 
echo $prompt;
# WAS echo $prompt'\c';
while 
	read line
do
	if [ x"$line" = 'x' ]
	then 
		cat -n $HOME/.cache
		echo Input a number or any UNIX  command
	else if expr "$line" : '-[0-9][0-9]*' >/dev/null
	then 
		n=`expr "$line" : '-\([0-9][0-9]*\)'`
		echo Delete $n
		sed "$n"d  <$HOME/.cache >$HOME/.newcache
		mv $HOME/.newcache $HOME/.cache
	else
	  case "$line" in
	  [1-9]) command=`sed -n "$line"'p' $HOME/.cache`;;
	  1[0-9]) command=`sed -n "$line"'p' $HOME/.cache` ;;
	  20) command=`sed -n "$line"'p' $HOME/.cache` ;;
	  *)	command="$line"
	  esac
	  xterm -e $command &
	  if fgrep -sx "$command" $HOME/.cache
	  then 
		n=`fgrep -xn "$command" $HOME/.cache|sed 's/:.*$//`
		if [ $n -gt 1 ]
		then
		  awk <$HOME/.cache >$HOME/.newcache '
		  NR<n-1{print}
		  NR==n-1{shunt=$0; print command}
		  NR==n{print shunt}
		  NR>n{print}
		  ' n=$n command="$command"
		else
		  cp $HOME/.cache $HOME/.newcache
		fi

	  else
		  (head -$NMINUS1 $HOME/.cache; echo "$command")>$HOME/.newcache
	  fi
	  mv $HOME/.newcache $HOME/.cache
	fi
	fi
	date
	cat -n $HOME/.cache
	echo $prompt;
	# was echo $prompt'\c';
done