EXAMPLES
       To see every process on the system using standard syntax:
          ps -e
          ps -ef
          ps -eF
          ps -ely

       To see every process on the system using BSD syntax:
          ps ax
          ps axu

       To print a process tree:
          ps -ejH
          ps axjf

       To get info about threads:
          ps -eLf
          ps axms

       To get security info:
          ps -eo euser,ruser,suser,fuser,f,comm,label
          ps axZ
          ps -eM

       To see every process running as root (real & effective ID) in user
       format:
          ps -U root -u root u

       To see every process with a user-defined format:
          ps -eo pid,tid,class,rtprio,ni,pri,psr,pcpu,stat,wchan:14,comm
          ps axo stat,euid,ruid,tty,tpgid,sess,pgrp,ppid,pid,pcpu,comm
          ps -Ao pid,tt,user,fname,tmout,f,wchan

       Print only the process IDs of syslogd:
          ps -C syslogd -o pid=

       Print only the name of PID 42:
          ps -q 42 -o comm=

SIMPLE PROCESS SELECTION
       a      Lift the BSD-style "only yourself" restriction, which is imposed upon the set of all processes when some BSD-style (without "-") options are
              used or when the ps personality setting is BSD-like.  The set of processes selected in this manner is in addition to the set of processes
              selected by other means.  An alternate description is that this option causes ps to list all processes with a terminal (tty), or to list all
              processes when used together with the x option.

       -A     Select all processes.  Identical to -e.

       -a     Select all processes except both session leaders (see getsid(2)) and processes not associated with a terminal.

       -d     Select all processes except session leaders.

       --deselect
              Select all processes except those that fulfill the specified conditions (negates the selection).  Identical to -N.

       -e     Select all processes.  Identical to -A.

       g      Really all, even session leaders.  This flag is obsolete and may be discontinued in a future release.  It is normally implied by the a flag, and
              is only useful when operating in the sunos4 personality.

       -N     Select all processes except those that fulfill the specified conditions (negates the selection).  Identical to --deselect.

       T      Select all processes associated with this terminal.  Identical to the t option without any argument.

       r      Restrict the selection to only running processes.

       x      Lift the BSD-style "must have a tty" restriction, which is imposed upon the set of all processes when some BSD-style (without "-") options are
              used or when the ps personality setting is BSD-like.  The set of processes selected in this manner is in addition to the set of processes
              selected by other means.  An alternate description is that this option causes ps to list all processes owned by you (same EUID as ps), or to
              list all processes when used together with the a option.

tingyang@TingYang:~$ ps -eF
UID PID PPID C SZ RSS PSR STIME TTY TIME CMD
root 1 0 0 39924 9104 0 20:35 ? 00:00:04 /sbin/init splash

tingyang@TingYang:~$ ps -aux
USER        PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root          1  0.0  0.4 159696  9104 ?        Ss   20:35   0:04 /sbin/init splash