 

   ...

  

  

   

   

  

   

   

    

  (regular expression)     
  .   Linux,   vi, emacs, grep, gawk 
sed,        .  
    ,      
.        ,   -
     . ,   -
     .

     ,  -
 ed, vi, emacs, grep, gawk  sed.  ,   -
     ,        "-
     "  7.