        ,     
 :     ,     -
.      ,  init 
 getty  mingetty,      
login:.        RETURN,  getty -
   login,       -
.       login   -
  .

 

Linux         PID
("process ID"   ).   ,  PID  -
:   .            
.      ,     PID
 ()    PID  .  
    ,         
   PID,      .

   ,  ,  ,  -
,   ps (  ).   ps   -1
      .   
ps,     CMD  bash,  , 
.     PID  PID .    
PP1D   PID   .    PID  PPID,
 ,  ,   (PID 2168)  
 ,  sleep (PID 2191). PID   sleep  PID
 (2168):

$ sleep 10 &

[1] 2891
$ ps -1

F S   UID   PID PPID  PRI NI ADDR   SZ WCHAN TTY        TIME CMD
100 S   500 2168 2167 0 72   0   -   454 wait4 pts/1   00:00:00 bash
000 S   500 2891 2168 0 63   0   -   286 nanosi pts/1   00:00:00 sleep
000 R   500 2892 2168 0 76   0   -   628 -      pts/1   00:00:00 ps

 ,     -1,    man-
  ps.      ps -1,   ,  -
     ,    sleep  
 :

$ sleep 10 S

[1] 2893
$ ps -1

F S   UID   PID PPID  PRI NI ADDR   SZ WCHAN TTY        TIME CMD
100 S   500 2168 2167 0 71   0   -   454 wait4 pts/1   00:00:00 bash
000 S   500 2893 2168 0 63   0   -   286 nanosi pts/1   00:00:00 sleep
000 R   500 2894 2168 0 75   0   -   628 -      pts/1   00:00:00 ps

 9.  II: Bourne Again Shell                                            297