PS命令对应的进程状态

The state is given by a sequence of characters, for example, ``RWNA''. The first character indicates the run state of the process:

           I       Marks a process that is idle (sleeping for longer than about 20 seconds).
           R       Marks a runnable process.
           S       Marks a process that is sleeping for less than about 20 seconds.
           T       Marks a stopped process.
           U       Marks a process in uninterruptible wait.
           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.
           >       The process has specified a soft limit on memory requirements and is currently exceeding that limit; such a process is (necessarily) not swapped.
           A       the process has asked for random page replacement (VA_ANOM, from vadvise(2), for example, lisp(1) in a garbage collect).
           E       The process is trying to exit.
           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 has asked for FIFO page replacement (VA_SEQL, from vadvise(2), for example, a large image processing program using virtual memory to sequentially
                   address voluminous data).
           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.