$ extest2

extest2 1: american
|     subtest 1: american
subtest 2: swiss
extest2 2: american

     american  cheese   -
       swiss.    -
    cheese      : american.

declare:      

  declare (  ,   typeset)  
    .   declare    -
  ;     :

1.  -   .

2.  -f     (  
 ""  28).

3.  -i        (
       ).

4.  -     .

5.  -    .

     ,   
 .      personi,   -
  alex:

$ declare personl=alex
$ declare -r person2=jenny
$ declare -rx person3=helen
$ declare -x person4

  readonly  export     declare -r
 declare -x .   ,    ,
       person4.   -
  person4  ,      -
    .

  declare       .  -
   persons:

$ declare -x -r person3=helen

 ,   -    +,   
  .      -
 persons    :

$ declare +r 

   declare   ,      -
 ,     ,   
 . ,  declare   -    -

 9.  11: Bourne Again Shell                                            307