$ cat days















$ sort days















. 5.6.  sort   

uniq:     

 uniq ("unique"  )  ,   -
 ,     .     ,  -
          ,  uniq 
  (. 5.7).

   ,     uniq,  uniq ,
       . (,  sort    
    -.)     man-
  uniq.

$ cat dups















$ uniq dups













. 5.7.  uniq   

162  II.   Red Hat Linux