查看linux占用内存的前十大程序：

 ps aux | sort -k4,4nr | head -n 10


sort这一部分：

-k, --key=KEYDEF

              sort via a key; KEYDEF gives location and type

k代表关键字，给定位置或者类型

 -r, --reverse

              reverse the result of comparisons

逆转排序，倒序输出

-n, --numeric-sort

              compare according to string numerical value

比较字符值

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.


下面列几条：

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