ps 命令中的進程狀態

 D    不可中斷睡眠 (通常是在IO操作)
R    正在運行或可運行（在運行隊列排隊中）
S    可中斷睡眠 (在等待某事件完成)
T    Stopped, either by a job control signal or because it is being traced.
W    正在換頁(2.6.內核之前有效)
X    死進程 (should never be seen)
Z    殭屍
I--空閒

BSD風格的
<    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