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linuxps

What does lowercase t means in ps state code

When I run ps xaf I have a following output:

ps xaf result

So my application has state code t+. But I can't find what it means. In man ps where is no such state code:

man ps

Does it equal to uppercase T state code? If it is, why do I always only get T state code when I do kill -SIGSTOP <pid>?

Solution

  • Not all versions of Linux know about the t code. It was introduced in 2.6.33 as tracing stop that is different from signal stop indicated by T. In the latest versions of proc(5) (2014-07-10 or later) you will find the following:

                        T  Stopped (on a signal) or (before Linux 2.6.33)
                       trace stopped
                    t  Tracing stop (Linux 2.6.33 onward)
                    W  Paging (only before Linux 2.6.0)
                    X  Dead (from Linux 2.6.0 onward)
                    x  Dead (Linux 2.6.33 to 3.13 only)
                    K  Wakekill (Linux 2.6.33 to 3.13 only)
                    W  Waking (Linux 2.6.33 to 3.13 only)
                    P  Parked (Linux 3.9 to 3.13 only)

    In addition to the usual R,S,D,Z,T,W status codes.

    See the latest version on Michael Kerrisk page.