Are tid and tgid always the same as pid in the output of ps?












2














In manpage of ps



tid         TID          the unique number representing a dispatchable
entity (alias lwp, spid). This value may also
appear as: a process ID (pid); a process group
ID (pgrp); a session ID for the session leader
(sid); a thread group ID for the thread group
leader (tgid); and a tty process group ID for
the process group leader (tpgid).

tgid TGID a number representing the thread group to which
a task belongs (alias pid). It is the process
ID of the thread group leader.


In Ubuntu, tid and tgid seem always the same as pid, for both user processes, and kernel threads (I run ps -o pid,tid,tgid,cmd) Is it true in Linux, and why?



Is it true in other Unix such as System V or BSD?



Thanks.










share|improve this question





























    2














    In manpage of ps



    tid         TID          the unique number representing a dispatchable
    entity (alias lwp, spid). This value may also
    appear as: a process ID (pid); a process group
    ID (pgrp); a session ID for the session leader
    (sid); a thread group ID for the thread group
    leader (tgid); and a tty process group ID for
    the process group leader (tpgid).

    tgid TGID a number representing the thread group to which
    a task belongs (alias pid). It is the process
    ID of the thread group leader.


    In Ubuntu, tid and tgid seem always the same as pid, for both user processes, and kernel threads (I run ps -o pid,tid,tgid,cmd) Is it true in Linux, and why?



    Is it true in other Unix such as System V or BSD?



    Thanks.










    share|improve this question



























      2












      2








      2







      In manpage of ps



      tid         TID          the unique number representing a dispatchable
      entity (alias lwp, spid). This value may also
      appear as: a process ID (pid); a process group
      ID (pgrp); a session ID for the session leader
      (sid); a thread group ID for the thread group
      leader (tgid); and a tty process group ID for
      the process group leader (tpgid).

      tgid TGID a number representing the thread group to which
      a task belongs (alias pid). It is the process
      ID of the thread group leader.


      In Ubuntu, tid and tgid seem always the same as pid, for both user processes, and kernel threads (I run ps -o pid,tid,tgid,cmd) Is it true in Linux, and why?



      Is it true in other Unix such as System V or BSD?



      Thanks.










      share|improve this question















      In manpage of ps



      tid         TID          the unique number representing a dispatchable
      entity (alias lwp, spid). This value may also
      appear as: a process ID (pid); a process group
      ID (pgrp); a session ID for the session leader
      (sid); a thread group ID for the thread group
      leader (tgid); and a tty process group ID for
      the process group leader (tpgid).

      tgid TGID a number representing the thread group to which
      a task belongs (alias pid). It is the process
      ID of the thread group leader.


      In Ubuntu, tid and tgid seem always the same as pid, for both user processes, and kernel threads (I run ps -o pid,tid,tgid,cmd) Is it true in Linux, and why?



      Is it true in other Unix such as System V or BSD?



      Thanks.







      linux ps thread system-v






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited Dec 29 '18 at 23:26









      ctrl-alt-delor

      10.9k41957




      10.9k41957










      asked Dec 29 '18 at 20:35









      Tim

      26.1k74246455




      26.1k74246455






















          1 Answer
          1






          active

          oldest

          votes


















          4














          You need to task ps to show thread information; otherwise it only lists processes:



          ps -eL -o pid,tid,comm | awk '$1 != $2'


          will show all the threads, apart from each process’ main thread, i.e. entries in the process table where pid and tid are different. The significant option is -L: without that, ps will only list entries where pid and tid are identical.



          On FreeBSD, the equivalent option is -H. I haven’t checked other BSDs, or System V.






          share|improve this answer























          • Hmm…this actually doesn't give an answer. Are they the same or not.
            – 炸鱼薯条德里克
            Dec 29 '18 at 20:52






          • 1




            @炸鱼薯条德里克 awk '$1 != $2' should give a strong hint, but I’ve clarified that part.
            – Stephen Kitt
            Dec 29 '18 at 20:54










          • Thanks. "On FreeBSD, the equivalent option is -H". BSD style option doesn't have dash, does it?
            – Tim
            Dec 29 '18 at 21:45








          • 1




            @Tim: Linux ps doesn't use a dash, but the actual FreeBSD ps accepts both kinds (because it doesn't have to distinguish: all options in FreeBSD ps are "BSD style" options) and the manual page actually documents them with a dash.
            – grawity
            Dec 29 '18 at 22:23











          Your Answer








          StackExchange.ready(function() {
          var channelOptions = {
          tags: "".split(" "),
          id: "106"
          };
          initTagRenderer("".split(" "), "".split(" "), channelOptions);

          StackExchange.using("externalEditor", function() {
          // Have to fire editor after snippets, if snippets enabled
          if (StackExchange.settings.snippets.snippetsEnabled) {
          StackExchange.using("snippets", function() {
          createEditor();
          });
          }
          else {
          createEditor();
          }
          });

          function createEditor() {
          StackExchange.prepareEditor({
          heartbeatType: 'answer',
          autoActivateHeartbeat: false,
          convertImagesToLinks: false,
          noModals: true,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: null,
          bindNavPrevention: true,
          postfix: "",
          imageUploader: {
          brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
          contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
          allowUrls: true
          },
          onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          });


          }
          });














          draft saved

          draft discarded


















          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f491508%2fare-tid-and-tgid-always-the-same-as-pid-in-the-output-of-ps%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown

























          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          4














          You need to task ps to show thread information; otherwise it only lists processes:



          ps -eL -o pid,tid,comm | awk '$1 != $2'


          will show all the threads, apart from each process’ main thread, i.e. entries in the process table where pid and tid are different. The significant option is -L: without that, ps will only list entries where pid and tid are identical.



          On FreeBSD, the equivalent option is -H. I haven’t checked other BSDs, or System V.






          share|improve this answer























          • Hmm…this actually doesn't give an answer. Are they the same or not.
            – 炸鱼薯条德里克
            Dec 29 '18 at 20:52






          • 1




            @炸鱼薯条德里克 awk '$1 != $2' should give a strong hint, but I’ve clarified that part.
            – Stephen Kitt
            Dec 29 '18 at 20:54










          • Thanks. "On FreeBSD, the equivalent option is -H". BSD style option doesn't have dash, does it?
            – Tim
            Dec 29 '18 at 21:45








          • 1




            @Tim: Linux ps doesn't use a dash, but the actual FreeBSD ps accepts both kinds (because it doesn't have to distinguish: all options in FreeBSD ps are "BSD style" options) and the manual page actually documents them with a dash.
            – grawity
            Dec 29 '18 at 22:23
















          4














          You need to task ps to show thread information; otherwise it only lists processes:



          ps -eL -o pid,tid,comm | awk '$1 != $2'


          will show all the threads, apart from each process’ main thread, i.e. entries in the process table where pid and tid are different. The significant option is -L: without that, ps will only list entries where pid and tid are identical.



          On FreeBSD, the equivalent option is -H. I haven’t checked other BSDs, or System V.






          share|improve this answer























          • Hmm…this actually doesn't give an answer. Are they the same or not.
            – 炸鱼薯条德里克
            Dec 29 '18 at 20:52






          • 1




            @炸鱼薯条德里克 awk '$1 != $2' should give a strong hint, but I’ve clarified that part.
            – Stephen Kitt
            Dec 29 '18 at 20:54










          • Thanks. "On FreeBSD, the equivalent option is -H". BSD style option doesn't have dash, does it?
            – Tim
            Dec 29 '18 at 21:45








          • 1




            @Tim: Linux ps doesn't use a dash, but the actual FreeBSD ps accepts both kinds (because it doesn't have to distinguish: all options in FreeBSD ps are "BSD style" options) and the manual page actually documents them with a dash.
            – grawity
            Dec 29 '18 at 22:23














          4












          4








          4






          You need to task ps to show thread information; otherwise it only lists processes:



          ps -eL -o pid,tid,comm | awk '$1 != $2'


          will show all the threads, apart from each process’ main thread, i.e. entries in the process table where pid and tid are different. The significant option is -L: without that, ps will only list entries where pid and tid are identical.



          On FreeBSD, the equivalent option is -H. I haven’t checked other BSDs, or System V.






          share|improve this answer














          You need to task ps to show thread information; otherwise it only lists processes:



          ps -eL -o pid,tid,comm | awk '$1 != $2'


          will show all the threads, apart from each process’ main thread, i.e. entries in the process table where pid and tid are different. The significant option is -L: without that, ps will only list entries where pid and tid are identical.



          On FreeBSD, the equivalent option is -H. I haven’t checked other BSDs, or System V.







          share|improve this answer














          share|improve this answer



          share|improve this answer








          edited Dec 29 '18 at 20:53

























          answered Dec 29 '18 at 20:46









          Stephen Kitt

          164k24365445




          164k24365445












          • Hmm…this actually doesn't give an answer. Are they the same or not.
            – 炸鱼薯条德里克
            Dec 29 '18 at 20:52






          • 1




            @炸鱼薯条德里克 awk '$1 != $2' should give a strong hint, but I’ve clarified that part.
            – Stephen Kitt
            Dec 29 '18 at 20:54










          • Thanks. "On FreeBSD, the equivalent option is -H". BSD style option doesn't have dash, does it?
            – Tim
            Dec 29 '18 at 21:45








          • 1




            @Tim: Linux ps doesn't use a dash, but the actual FreeBSD ps accepts both kinds (because it doesn't have to distinguish: all options in FreeBSD ps are "BSD style" options) and the manual page actually documents them with a dash.
            – grawity
            Dec 29 '18 at 22:23


















          • Hmm…this actually doesn't give an answer. Are they the same or not.
            – 炸鱼薯条德里克
            Dec 29 '18 at 20:52






          • 1




            @炸鱼薯条德里克 awk '$1 != $2' should give a strong hint, but I’ve clarified that part.
            – Stephen Kitt
            Dec 29 '18 at 20:54










          • Thanks. "On FreeBSD, the equivalent option is -H". BSD style option doesn't have dash, does it?
            – Tim
            Dec 29 '18 at 21:45








          • 1




            @Tim: Linux ps doesn't use a dash, but the actual FreeBSD ps accepts both kinds (because it doesn't have to distinguish: all options in FreeBSD ps are "BSD style" options) and the manual page actually documents them with a dash.
            – grawity
            Dec 29 '18 at 22:23
















          Hmm…this actually doesn't give an answer. Are they the same or not.
          – 炸鱼薯条德里克
          Dec 29 '18 at 20:52




          Hmm…this actually doesn't give an answer. Are they the same or not.
          – 炸鱼薯条德里克
          Dec 29 '18 at 20:52




          1




          1




          @炸鱼薯条德里克 awk '$1 != $2' should give a strong hint, but I’ve clarified that part.
          – Stephen Kitt
          Dec 29 '18 at 20:54




          @炸鱼薯条德里克 awk '$1 != $2' should give a strong hint, but I’ve clarified that part.
          – Stephen Kitt
          Dec 29 '18 at 20:54












          Thanks. "On FreeBSD, the equivalent option is -H". BSD style option doesn't have dash, does it?
          – Tim
          Dec 29 '18 at 21:45






          Thanks. "On FreeBSD, the equivalent option is -H". BSD style option doesn't have dash, does it?
          – Tim
          Dec 29 '18 at 21:45






          1




          1




          @Tim: Linux ps doesn't use a dash, but the actual FreeBSD ps accepts both kinds (because it doesn't have to distinguish: all options in FreeBSD ps are "BSD style" options) and the manual page actually documents them with a dash.
          – grawity
          Dec 29 '18 at 22:23




          @Tim: Linux ps doesn't use a dash, but the actual FreeBSD ps accepts both kinds (because it doesn't have to distinguish: all options in FreeBSD ps are "BSD style" options) and the manual page actually documents them with a dash.
          – grawity
          Dec 29 '18 at 22:23


















          draft saved

          draft discarded




















































          Thanks for contributing an answer to Unix & Linux Stack Exchange!


          • Please be sure to answer the question. Provide details and share your research!

          But avoid



          • Asking for help, clarification, or responding to other answers.

          • Making statements based on opinion; back them up with references or personal experience.


          To learn more, see our tips on writing great answers.





          Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


          Please pay close attention to the following guidance:


          • Please be sure to answer the question. Provide details and share your research!

          But avoid



          • Asking for help, clarification, or responding to other answers.

          • Making statements based on opinion; back them up with references or personal experience.


          To learn more, see our tips on writing great answers.




          draft saved


          draft discarded














          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f491508%2fare-tid-and-tgid-always-the-same-as-pid-in-the-output-of-ps%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown





















































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown

































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown







          Popular posts from this blog

          Сан-Квентин

          Алькесар

          Josef Freinademetz