
  NNAAMMEE

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

  SSYYNNOOPPSSIISS

  wwhhiilleetest body

  DDEESSCCRRIIPPTTIIOONN

  The wwhhiillee command evaluates test as an expression (in the same way that
  _ee_xx_pp_rr 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. _CC_oo_nn_tt_ii_nn_uu_ee commands may be executed inside body to terminate
  the current iteration of the loop, and _bb_rr_ee_aa_kk commands may be executed
  inside body to cause immediate termination of the wwhhiillee command. The wwhhiillee
  command always returns an empty string.

  Note: test should almost always be enclosed in braces. If not, variable
  substitutions will be made before the wwhhiillee 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x<<1100:

    set x 0
    while {$x<10} {
    	puts "x is $x"
    	incr x
    }

  SSEEEE AALLSSOO

  _bb_rr_ee_aa_kk, _cc_oo_nn_tt_ii_nn_uu_ee, _ff_oo_rr, _ff_oo_rr_ee_aa_cc_hh

  KKEEYYWWOORRDDSS

  _b_o_o_l_e_a_n_ _v_a_l_u_e, _l_o_o_p, _t_e_s_t, _w_h_i_l_e
  ---------------------------------------------------------------------------

    _C_o_p_y_r_i_g_h_t  1993 The Regents of the University of California.
    _C_o_p_y_r_i_g_h_t  1994-1997 Sun Microsystems, Inc.
    _C_o_p_y_r_i_g_h_t  1995-1997 Roger E. Critchlow Jr.

