  ,  whoson,   ,     -
 ,        .

   whoson        -
   .   ,      -
  bash (bash whoson).  bash    -
   .    bash   , a whoson 
,  ,    whoson 
  .

   ,   ,   
chmod (.  "chmod:   "  6).  . 9.1  
 Is   -1,      whoson  -
 chmod   ,         .

$ Is -I whoson

-rw-rw-r--   1 alex    group          40 May 24 11:30 whoson

$ chmod u+x whoson
$ Is -1 whoson

-rwxrw-r-- 1 alex      group          40 May 24 11:30 whoson

$ whoson

Sat May 24 11:40:49 PST 2003

,   

jenny    pts/7    May 23 18:17

his      pts/1    May 24 09:59

scott    pts/12   May 24 06:29 (bravo.tcorp.com)

alex     pts/4    May 24 09:08

. 9.1.        
 chmod



  ?         whoson 
    bash: whoson: command not found ( 
), , ,        
   .   :

$ ./whoson

 ./        . -
  ,      -
,    "PATH:    "    .

  Is      (-),  ,   -
      .   chmod   -
  .  u+x  chmod  (+)   
()  (). (   user (),    
,        .)   -
  .   Is      ,  -
,        .

       ,    
    /  .    
     ,       -

284                                       III.   Red Hat Linux