Different outputs for `w`, `who`, `whoami` and `id`












1















In command line platforms online, like for instance the one on Codecademy, when I run



for cmd in w who whoami id
do
echo $cmd
$cmd
echo =========================
echo " "
done


I get



w                                                                                                   
00:52:54 up 8 days, 14:10,  0 users,  load average: 3.78, 2.98, 2.69                               
USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT                                 
=========================                                                                           
                                                                                                    
who                                                                                                 
=========================                                                                           
                                                                                                    
whoami                                                                                              
ccuser                                                                                              
=========================                                                                           
                                                                               
id                                                                        
uid=1000(ccuser) gid=1000(ccuser) groups=1000(ccuser)                          
=========================                                                                    


Note that only whoami and id output something. When I run the same thing on my computer, I see similar results for all commands.



Why doesn't Codecademy display the user for w and who? What's different about these commands?










share|improve this question







New contributor




whoami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

























    1















    In command line platforms online, like for instance the one on Codecademy, when I run



    for cmd in w who whoami id
    do
    echo $cmd
    $cmd
    echo =========================
    echo " "
    done


    I get



    w                                                                                                   
    00:52:54 up 8 days, 14:10,  0 users,  load average: 3.78, 2.98, 2.69                               
    USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT                                 
    =========================                                                                           
                                                                                                        
    who                                                                                                 
    =========================                                                                           
                                                                                                        
    whoami                                                                                              
    ccuser                                                                                              
    =========================                                                                           
                                                                                   
    id                                                                        
    uid=1000(ccuser) gid=1000(ccuser) groups=1000(ccuser)                          
    =========================                                                                    


    Note that only whoami and id output something. When I run the same thing on my computer, I see similar results for all commands.



    Why doesn't Codecademy display the user for w and who? What's different about these commands?










    share|improve this question







    New contributor




    whoami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
    Check out our Code of Conduct.























      1












      1








      1


      1






      In command line platforms online, like for instance the one on Codecademy, when I run



      for cmd in w who whoami id
      do
      echo $cmd
      $cmd
      echo =========================
      echo " "
      done


      I get



      w                                                                                                   
      00:52:54 up 8 days, 14:10,  0 users,  load average: 3.78, 2.98, 2.69                               
      USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT                                 
      =========================                                                                           
                                                                                                          
      who                                                                                                 
      =========================                                                                           
                                                                                                          
      whoami                                                                                              
      ccuser                                                                                              
      =========================                                                                           
                                                                                     
      id                                                                        
      uid=1000(ccuser) gid=1000(ccuser) groups=1000(ccuser)                          
      =========================                                                                    


      Note that only whoami and id output something. When I run the same thing on my computer, I see similar results for all commands.



      Why doesn't Codecademy display the user for w and who? What's different about these commands?










      share|improve this question







      New contributor




      whoami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.












      In command line platforms online, like for instance the one on Codecademy, when I run



      for cmd in w who whoami id
      do
      echo $cmd
      $cmd
      echo =========================
      echo " "
      done


      I get



      w                                                                                                   
      00:52:54 up 8 days, 14:10,  0 users,  load average: 3.78, 2.98, 2.69                               
      USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT                                 
      =========================                                                                           
                                                                                                          
      who                                                                                                 
      =========================                                                                           
                                                                                                          
      whoami                                                                                              
      ccuser                                                                                              
      =========================                                                                           
                                                                                     
      id                                                                        
      uid=1000(ccuser) gid=1000(ccuser) groups=1000(ccuser)                          
      =========================                                                                    


      Note that only whoami and id output something. When I run the same thing on my computer, I see similar results for all commands.



      Why doesn't Codecademy display the user for w and who? What's different about these commands?







      users who w whoami






      share|improve this question







      New contributor




      whoami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      share|improve this question







      New contributor




      whoami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.









      share|improve this question




      share|improve this question






      New contributor




      whoami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.









      asked 2 hours ago









      whoamiwhoami

      61




      61




      New contributor




      whoami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.





      New contributor





      whoami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






      whoami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






















          1 Answer
          1






          active

          oldest

          votes


















          3
















          • id reports


            • the current credentials of its own process; or

            • the credentials of a named user, as read out of the system account database.




          • whoami reports the current credentials of its own process.


          • who and w report the active login sessions table from the login database.


          BSD doco notes that whoami does a subset of the job of id, and that id renders it obsolete.



          A system does not have to have an active login sessions table. On Linux operating systems and on the BSDs, if the table has not been created at bootstrap, or has been deleted since, the system will operate without one. Logging in and out does not implicitly create it on Linux operating systems, moreover.



          Furthermore, the table need not be readable by unprivileged users and neither the who nor the w command will report this as an error.



          Further reading




          • Jonathan de Boyne Pollard (2018). The Unix login database. Frequently Given Answers.

          • Jonathan de Boyne Pollard (2018). "login-update-utmpx". User Commands. nosh toolset.

          • Lennart Poettering et al. (2018). systemd-update-utmp.service. systemd manual pages. Freedesktop.org.

          • Is it necessary for a login-shell to create utmp entry?

          • https://unix.stackexchange.com/a/409036/5132






          share|improve this answer

























            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
            });


            }
            });






            whoami is a new contributor. Be nice, and check out our Code of Conduct.










            draft saved

            draft discarded


















            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f506757%2fdifferent-outputs-for-w-who-whoami-and-id%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









            3
















            • id reports


              • the current credentials of its own process; or

              • the credentials of a named user, as read out of the system account database.




            • whoami reports the current credentials of its own process.


            • who and w report the active login sessions table from the login database.


            BSD doco notes that whoami does a subset of the job of id, and that id renders it obsolete.



            A system does not have to have an active login sessions table. On Linux operating systems and on the BSDs, if the table has not been created at bootstrap, or has been deleted since, the system will operate without one. Logging in and out does not implicitly create it on Linux operating systems, moreover.



            Furthermore, the table need not be readable by unprivileged users and neither the who nor the w command will report this as an error.



            Further reading




            • Jonathan de Boyne Pollard (2018). The Unix login database. Frequently Given Answers.

            • Jonathan de Boyne Pollard (2018). "login-update-utmpx". User Commands. nosh toolset.

            • Lennart Poettering et al. (2018). systemd-update-utmp.service. systemd manual pages. Freedesktop.org.

            • Is it necessary for a login-shell to create utmp entry?

            • https://unix.stackexchange.com/a/409036/5132






            share|improve this answer






























              3
















              • id reports


                • the current credentials of its own process; or

                • the credentials of a named user, as read out of the system account database.




              • whoami reports the current credentials of its own process.


              • who and w report the active login sessions table from the login database.


              BSD doco notes that whoami does a subset of the job of id, and that id renders it obsolete.



              A system does not have to have an active login sessions table. On Linux operating systems and on the BSDs, if the table has not been created at bootstrap, or has been deleted since, the system will operate without one. Logging in and out does not implicitly create it on Linux operating systems, moreover.



              Furthermore, the table need not be readable by unprivileged users and neither the who nor the w command will report this as an error.



              Further reading




              • Jonathan de Boyne Pollard (2018). The Unix login database. Frequently Given Answers.

              • Jonathan de Boyne Pollard (2018). "login-update-utmpx". User Commands. nosh toolset.

              • Lennart Poettering et al. (2018). systemd-update-utmp.service. systemd manual pages. Freedesktop.org.

              • Is it necessary for a login-shell to create utmp entry?

              • https://unix.stackexchange.com/a/409036/5132






              share|improve this answer




























                3












                3








                3









                • id reports


                  • the current credentials of its own process; or

                  • the credentials of a named user, as read out of the system account database.




                • whoami reports the current credentials of its own process.


                • who and w report the active login sessions table from the login database.


                BSD doco notes that whoami does a subset of the job of id, and that id renders it obsolete.



                A system does not have to have an active login sessions table. On Linux operating systems and on the BSDs, if the table has not been created at bootstrap, or has been deleted since, the system will operate without one. Logging in and out does not implicitly create it on Linux operating systems, moreover.



                Furthermore, the table need not be readable by unprivileged users and neither the who nor the w command will report this as an error.



                Further reading




                • Jonathan de Boyne Pollard (2018). The Unix login database. Frequently Given Answers.

                • Jonathan de Boyne Pollard (2018). "login-update-utmpx". User Commands. nosh toolset.

                • Lennart Poettering et al. (2018). systemd-update-utmp.service. systemd manual pages. Freedesktop.org.

                • Is it necessary for a login-shell to create utmp entry?

                • https://unix.stackexchange.com/a/409036/5132






                share|improve this answer

















                • id reports


                  • the current credentials of its own process; or

                  • the credentials of a named user, as read out of the system account database.




                • whoami reports the current credentials of its own process.


                • who and w report the active login sessions table from the login database.


                BSD doco notes that whoami does a subset of the job of id, and that id renders it obsolete.



                A system does not have to have an active login sessions table. On Linux operating systems and on the BSDs, if the table has not been created at bootstrap, or has been deleted since, the system will operate without one. Logging in and out does not implicitly create it on Linux operating systems, moreover.



                Furthermore, the table need not be readable by unprivileged users and neither the who nor the w command will report this as an error.



                Further reading




                • Jonathan de Boyne Pollard (2018). The Unix login database. Frequently Given Answers.

                • Jonathan de Boyne Pollard (2018). "login-update-utmpx". User Commands. nosh toolset.

                • Lennart Poettering et al. (2018). systemd-update-utmp.service. systemd manual pages. Freedesktop.org.

                • Is it necessary for a login-shell to create utmp entry?

                • https://unix.stackexchange.com/a/409036/5132







                share|improve this answer














                share|improve this answer



                share|improve this answer








                edited 51 mins ago

























                answered 1 hour ago









                JdeBPJdeBP

                36.9k475176




                36.9k475176






















                    whoami is a new contributor. Be nice, and check out our Code of Conduct.










                    draft saved

                    draft discarded


















                    whoami is a new contributor. Be nice, and check out our Code of Conduct.













                    whoami is a new contributor. Be nice, and check out our Code of Conduct.












                    whoami is a new contributor. Be nice, and check out our Code of Conduct.
















                    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.




                    draft saved


                    draft discarded














                    StackExchange.ready(
                    function () {
                    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f506757%2fdifferent-outputs-for-w-who-whoami-and-id%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

                    A CLEAN and SIMPLE way to add appendices to Table of Contents and bookmarks

                    Calculate evaluation metrics using cross_val_predict sklearn

                    Insert data from modal to MySQL (multiple modal on website)