 ,         0.
      ,    temp,  -
  tempcopy.         .
(      ,    : . man-
  .)       ,   
 ,      .   -
:     ,    . 
     ,      -
.         RETURN.



   ,   .   -
   ,     .
     ,   
.

     ,   
.   ,     . 
    ,    .   GNU  -
   ,    --help  ( -
)   .

 . 7.1  ,  ,    Is  . 
 Is       , -
   .   ,   - ( (reverse) -
;    GNU,      --reverse) -
  Is       ,   
  .  -   Is     -
   .

$ Is

alex  house  mark   office    personal  test

hold  jenny  names  oldstuff  temp

$ Is -r

test  personal  office  mark  house  alex

temp  oldstuff  names  jenny  hold

$ Is -x

alex    hold      house     jenny  mark  names

office  oldstuff  personal  temp   test

$ Is -rx

test  temp   personal  oldstuff  office  names

mark  jenny  house     hold      alex

. 7.1.  

    ,     -
     ,   ;   
  .      ,  -
   .       -

 7.  1: Bourne Again Shell                                            223