ps - Process Status

state     The state is given by a sequence of characters, for example, "RWNA". The first character indicates the run state of the process: D     Marks a process in disk (or other short term, uninterruptible) wait. I     Marks a process that is idle (sleeping for longer than about 20 seconds). L     Marks a process that is waiting to acquire a lock. R     Marks a runnable process. S     Marks a process that is sleeping for less than about 20 seconds. T     Marks a stopped process. W     Marks an idle interrupt thread. Z     Marks a dead process (a "zombie"). Additional characters after these, if any, indicate additional state information: +     The process is in the foreground process group of its control terminal. <     The process has raised CPU scheduling priority. E     The process is trying to exit. J     Marks a process which is in jail(2). The hostname of the prison can be found in /proc/<pid/status>. L     The process has pages locked in core (for example, for raw I/O). N     The process has reduced CPU scheduling priority (see setpriority(2)). s     The process is a session leader. V     The process is suspended during a vfork(2). W     The process is swapped out. X     The process is being traced or debugged. [링크 : http://www.gsp.com/cgi-bin/man.cgi?section=1&topic=ps]