NAME
       while  -  Execute script repeatedly as long as a condition
       is met

SYNOPSIS
       while test body


DESCRIPTION
       The while command evaluates test as an expression (in  the
       same  way that expr evaluates its argument).  The value of
       the expression must a proper boolean value;  if  it  is  a
       true  value then body is executed by passing it to the Tcl
       interpreter.  Once body has been  executed  then  test  is
       evaluated  again, and the process repeats until eventually
       test  evaluates  to  a  false  boolean  value.    Continue
       commands  may  be  executed  inside  body to terminate the
       current iteration of the loop, and break commands  may  be
       executed inside body to cause immediate termination of the
       while command.  The while command always returns an  empty
       string.

       Note: test should almost always be enclosed in braces.  If
       not, variable substitutions will be made before the  while
       command   starts  executing,  which  means  that  variable
       changes made by the loop body will not  be  considered  in
       the  expression.   This is likely to result in an infinite
       loop.   If  test   is   enclosed   in   braces,   variable
       substitutions   are   delayed   until  the  expression  is
       evaluated (before each loop iteration), so changes in  the
       variables  will  be  visible.   For  an  example,  try the
       following script with and without the braces around $x<10:
              set x 0
              while {$x<10} {
                puts "x is $x"
                incr x
              }


KEYWORDS
