## In linux,
## find zombie process , grep Z or 'defunc'
host:~$ ps aux | grep Z
host:~$ ps aux | grep defunc
option: a : all with tty, include other users
u : display user-oriented format
x : processes without controlling ttys
## parent process must be killed to kill zombie prcess, find parent , using 'pstree'
host:~$ pstree -paul
options :
-p : show pids
-a : show ommand line arguments
-u : show uid transitions
-l : don't truncate long lines
