ps -aux 命令详解

示例：

系统内存状况：
                total             used             free        shared     buffers        cached
Mem:      12147396   11982020     165376          0        39408        4487020

ps -aux 拿出来一个例子：

USER     PID         %CPU    %MEM    VSZ           RSS          TTY      STAT    START   TIME             COMMAND

root        17099      143        1.0          3659280   129980      ?          Sl          Feb26   14654:43             ./a.out  -100

解释：

VSZ: 程序占用的总虚拟内存大小（3659280 KB）

virtual memory size of the process in KiB (1024-byte units). Device mappings are currently excluded; this is subject to change. (alias vsize). 

  

RSS: 程序占用的常住内存，也就是不可以被替换到交换区的内存大小（129980 KB）

   resident set size, the non-swapped physical memory that a task has used (in kiloBytes). (alias rssize, rsz).

STAT: 程序的状态，详解见最后：PROCESS STATE CODES（ Sl， 正在睡眠，可以中断，多线程）

   multi-character process state. See section PROCESS STATE CODES for the different values meaning.See  also s and state if you just want the first character displayed.

TTY: 程序所属的终端，如果是？， 代表是后台程序

   controlling tty (terminal). (alias tname, tt).

START: 程序开始时间（2月26号）

time the command started. If the process was started less than 24 hours ago, the output format is"HH:MM:SS", else it is "  <mm dd" (where Mmm is a three-letter month name).

%MEM: 程序占用的常住内存大小在系统总内存中的比例，ie： RSS / total（129980/12147396）

 ratio of the process's resident set size  to the physical memory on the machine, expressed as apercentage. (alias pmem).

%CPU: 程序占用各个CPU时间之和除以程序运行总时间，所以如果是多核系统，这个值可能大于100, 本例143

   cpu utilization of the process in "##.#" format. Currently, it is the CPU time used divided by the time theprocess has been running (cputime/realtime ratio),  expressed as a percentage. It will not add up to 100%unless you are lucky. (alias pcpu). It can be larger than 100% when your machine is multi-CPU.

PROCESS STATE CODES
       Here are the different values that the s, stat and state output specifiers (header "STAT" or "S") will display to describe the state of a process:
       D    uninterruptible sleep (usually IO)
       R    running or runnable (on run queue)
       S    interruptible sleep (waiting for an event to complete)
       T    stopped, either by a job control signal or because it is being traced.
       W    paging (not valid since the 2.6.xx kernel)
       X    dead (should never be seen)
       Z    defunct ("zombie") process, terminated but not reaped by its parent.


       For BSD formats and when the stat keyword is used, additional characters may be displayed:
       <    high-priority (not nice to other users)
       N    low-priority (nice to other users)
       L    has pages locked into memory (for real-time and custom IO)
       s    is a session leader
       l    is multi-threaded (using CLONE_THREAD, like NPTL pthreads do)

       +    is in the foreground process group.

ps： 看了好多文章，还是man ps的结果最给力！！！！！