linux ps 命令查看进程状态

linux上进程有5种状态: 
1. 运行(正在运行或在运行队列中等待) 
2. 中断(休眠中, 受阻, 在等待某个条件的形成或接受到信号) 
3. 不可中断(收到信号不唤醒和不可运行, 进程必须等待直到有中断发生) 
4. 僵死(进程已终止, 但进程描述符存在, 直到父进程调用wait4()系统调用后释放) 
5. 停止(进程收到SIGSTOP, SIGSTP, SIGTIN, SIGTOU信号后停止运行运行)

ps工具标识进程的5种状态码: 
D 不可中断 uninterruptible sleep (usually IO) 
R 运行 runnable (on run queue) 
S 中断 sleeping 
T 停止 traced or stopped 
Z 僵死 a defunct ("zombie") process

注: 其它状态还包括W(无驻留页), <(高优先级进程), N(低优先级进程), L(内存锁页).

使用ps格式输出来查看进程状态: 
ps -eo user,stat..,cmd

user          用户名 
uid           用户号 
pid           进程号 
ppid          父进程号 
'size'          内存大小, Kbytes字节. 
v'size'         总虚拟内存大小, bytes字节(包含code+data+stack) 
share         总共享页数 
nice          进程优先级(缺省为0, 最大为-20) 
priority(pri) 内核调度优先级 
pmem          进程分享的物理内存数的百分比 
trs           程序执行代码驻留大小 
rss           进程使用的总物理内存数, Kbytes字节 
time          进程执行起到现在总的CPU暂用时间 
stat          进程状态 
cmd(args)     执行命令的简单格式

例子: 
查看当前系统进程的uid,pid,stat,pri, 以uid号排序. 
ps -eo pid,stat,pri,uid --sort uid

查看当前系统进程的user,pid,stat,rss,args, 以rss排序. 
ps -eo user,pid,stat,rss,args --sort rss  

附：

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