'while' construct, which enables users to
iterate while a particular expression evaluates to TRUE
The while can be streteched over multiple lines if desired
The <condition> part can be a CLI that supports PRC, a pipeline,
a builtin function, a logical expression, or an arithmetic expression
Here are some examples

 router> let x=0
 router> while (( x++ < 10 )); do
 do..done> echo $x
 do..done> done
 router>

Notice that the prompt changes while entering the echo and done statements
this is true of other constructs in IOS.sh as well

Another example might be as follows:
 router> while ping $Address | grep -p Success; do
 do..done>sleep 2
 do..done>printf \"still alive!\"
 do..done>done

Please note that while loops may be exited by using Ctrl-C or the traditional
IOS exit keys