   ,      . -
    passwd  "",  
     who:

who:x:1000:1000:execute who:/usr:/usr/bin/who

 who        
,   who    .   -
 who       ,    
 who      .  -
   passwd   ;   
 who      .
       , -
     . ,   
    FTP (.  19)   
FTP-   .         
,    /bin/false (   ) 
 /sbin/nologin (     ).   -
   /etc/nologin.txt,   nologin    (
   ,      who:   
  ,    ).

     .   -
        /etc/passwd.  
   ,      ,   
 .       -
,    .

/etc/printcap.    .    
    4.3BSD UNIX.

/etc/profile.        -
  ,     .     -
          ,   .
(       
   . ()   "    
  . ()  source"  9.)    
      ,   -
     .     
   ,  ,   -
   . .   "~/.bash_profile".
    /etc/profile,     (
/etc/motd),     (umask)   
   <CONTROL+C>:

# cat /etc/profile

cat /etc/motd
umask 022
stty intr '"'

       /etc/profile  .
 12. ,                                    453