        -
     .

       login   
 PreSession       -
   ,      
   ,     .

 login   PreSession    HOME,
PATH, LOGNAME, SHELL, TERM  MAIL.   ,    -
,    /etc/group (.  "   "
 12).    login      ,
  ,   login.   
 PreSession    .

        
        
 /etc/profile  /etc/bashrc.     
  .     ,  
,       /etc/motd ( ) 
/etc/issue,         -
  umask (.  "umask"  " Linux"    ).

         -
  ,     .   -
   . 9.1.       
,        -
,  ,        .

     

          
.        ,  
  .      -
,      .   
       in it,   
  .     init  , -
    /etc/inittab.     -
 , init   mingetty,     
.

      5    GUI-, -
  GNOME (gdm)     .

 

 shutdown  halt   ,    -
 .     ,    -
,     ,    -
    .   halt   poweroff
 reboot.    halt       ( -
 0)   ( 6),  halt  shutdown. (  

 11.  :                     413