Any command to watch output repeatedly??

Hi Experts,,

Can you tell me "Is there any command in solaris that gives the output repeatedly for every x seconds" when used with other commands like ls,du,df,etc..Like prstat updates its output for every 5 seconds..

If i want to view how much of disk usage is going on a filesystem for every x seconds..when i am installing a software/package ...what i need to do..Is there any command in solaris which satisfies this requirement...or should we need to write some script to satisfy this...

My search doen't resulted much about that..but i found that there is a command called "watch" in linux which completely satisfies this requirement...

How to use the watch command, by The Linux Information Project (LINFO)

Want everyone to share their knowledge to get a solution to this...

Not really sure for solaris, but you always can have simple script like...

while true;do
command
sleep 5
done

This will display command output every 5s until u break it...

"yes" repeatedly outputs the result of command