ps -aux 命令 与 ps aux命令

man ps 之后得到的结果：
ps displays information about a selection of the active processes. If
you want a repetitive update of the selection and the displayed
information, use top(1) instead.


Note that "ps -aux" is distinct from "ps aux". The POSIX and UNIX
standards require that "ps -aux" print all processes owned by a user
named "x",
as well as printing all processes that would be selected by
the -a option. If the user named "x" does not exist, this ps may
interpret the command as "ps aux" instead and print a warning.
This behavior is intended to aid in transitioning old scripts and habits. It
is fragile, subject to change, and thus should not be relied upon.


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 -eopid,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 -p 42 -o comm=