0 II:
Bourne Again Shell

  ...

    

    

   

  

    

   

 

   

 

   

Bourne Again Shell (bash)       
.     bash  ,
       .    
     ,   ,
    (shell script).    , -
       (,  for 
 if).

^^^k         .     
^!^^  ,    .    
^      ,   GUI- (.  "-
^^           "  4)    -
 (.  "  "  4).