Command
	while

Purpose
	Creates and executes a command or a command block repeatedly.

Aliases
	while

Syntax
	while <condition>
	    <line>


Options
	None.

Arguments
	<condition>	An expression resulting in a bool constant.
	<line>	The line to execute repeatedly as long as <condition> is true.

	<line> can have one command, or a block of commands enclosed within do...done.

Stream Input	
	Ignored.

Stream Output
	None.

Stream Error
	Any errors are listed here.

Description
	while is a programming construct that allows the user to repeatedly execute one commands or
	a block of commands.

	<condition> is evaluated at runtime, and not when the command is first entered.
	(Since the while, and any other command, can be inside another programming construct, function, script etc.,
	its run-time value may not be necessarily the same as its parse-time value.)

	Nesting of all programming constructs (while, if...else...endif, do...done, function, etc.) is allowed.
	There is no limit on how many levels of nesting can be done.

	<condition> can contain AND, OR, and NOT bool operators. It is recommended that you use parentheses when
	using these operators. There is no limit on how many, or how many levels of, parentheses can be used.
	
Restrictions
	Stream redirection is not allowed on the while command. However, command within <line>, and within
	do-done command-block used in place of <line>, can contain their own stream redirection.

Valid Examples
	var int i
	while ($i<50)
	do
	    set $i = $i+1
	    echo ($i*$i)
	done

	Will print squares of integers between 1 and 50.


Invalid Examples
	var int i
	while ($i)
	do
	    set $i = $i+1
	    echo ($i*$i)
	done

	Will produce error. The expression ($i) does not evaluate to a bool value, and thus, it is not a valid
	condition.

	var int i
	while ($i<50)
	    echo ($i*$i)
	    set $i = $i+1

	The above will go into an infinite loop since the only command executed repeatedly is the echo command. $i
	never gets incremented. This could happen if one forgets to put a do...done block after a while command.

See Also
break
do
if