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Serial Port configuration in RHEL

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  • N Offline
    N Offline
    Nimika
    wrote on last edited by
    #14

    Thankyou both of you.
    Please tell me how to add my normal user to the dialout group?
    What is dialout group?

    mrjjM jsulmJ 2 Replies Last reply
    1
    • K Offline
      K Offline
      kuzulis
      Qt Champions 2020
      wrote on last edited by
      #15

      QIODevice::OpenMode mode = QIODevice::ReadOnly | QIODevice::Unbuffered;

      Did you read documentation? QIODevice::Unbuffered it is unsupported mode.

      N 1 Reply Last reply
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      • K kuzulis

        QIODevice::OpenMode mode = QIODevice::ReadOnly | QIODevice::Unbuffered;

        Did you read documentation? QIODevice::Unbuffered it is unsupported mode.

        N Offline
        N Offline
        Nimika
        wrote on last edited by
        #16

        @kuzulis Yeah I made it as comment.

        1 Reply Last reply
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        • N Nimika

          Thankyou both of you.
          Please tell me how to add my normal user to the dialout group?
          What is dialout group?

          mrjjM Offline
          mrjjM Offline
          mrjj
          Lifetime Qt Champion
          wrote on last edited by mrjj
          #17

          @Nimika

          • Please tell me how to add my normal user to the dialout group?
            sudo usermod -a -G dialout theuser

          • What is dialout group?
            Its a predefined group found in many distros.
            From old times it was used to allowed modems
            to make connection etc. ( ie allow the user to connect to the internet :)

          So often the system has this group and any user in it, have access to /dev/ttySX

          N 1 Reply Last reply
          1
          • N Nimika

            Thankyou both of you.
            Please tell me how to add my normal user to the dialout group?
            What is dialout group?

            jsulmJ Offline
            jsulmJ Offline
            jsulm
            Lifetime Qt Champion
            wrote on last edited by
            #18

            @Nimika You really should learn how user/groups and access rights management is working on UNIX/Linux.

            https://forum.qt.io/topic/113070/qt-code-of-conduct

            1 Reply Last reply
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            • N Offline
              N Offline
              Nimika
              wrote on last edited by
              #19

              @jsulm Actually my system is Red Hat Enterprise Linux based so it is different to use its commands.

              1 Reply Last reply
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              • mrjjM mrjj

                @Nimika

                • Please tell me how to add my normal user to the dialout group?
                  sudo usermod -a -G dialout theuser

                • What is dialout group?
                  Its a predefined group found in many distros.
                  From old times it was used to allowed modems
                  to make connection etc. ( ie allow the user to connect to the internet :)

                So often the system has this group and any user in it, have access to /dev/ttySX

                N Offline
                N Offline
                Nimika
                wrote on last edited by
                #20

                @mrjj Thank you !! let me add it now and search whether it will work or not.....

                mrjjM 1 Reply Last reply
                0
                • N Nimika

                  @mrjj Thank you !! let me add it now and search whether it will work or not.....

                  mrjjM Offline
                  mrjjM Offline
                  mrjj
                  Lifetime Qt Champion
                  wrote on last edited by mrjj
                  #21

                  @Nimika
                  Np. as far as I can see it's the same for Red Hat with ttySX access, so there is
                  tons on google on the topic on allowing user X to read and write to /dev/ttSxxx
                  stuff.
                  http://ithelpblog.com/os/linux/bashandscripts/howto-add-user-to-group-on-linux-redhat-rhel-centos-fedora/

                  1 Reply Last reply
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                  • SGaistS SGaist

                    NEVER EVER use root like that. All the more when developing. It's bad practice and doing so you're opening a gaping security hole.

                    Add your normal user to the dialout group and be done with it.

                    N Offline
                    N Offline
                    Nimika
                    wrote on last edited by
                    #22

                    @SGaist Can I use serial ports to any user other than root?

                    mrjjM 1 Reply Last reply
                    0
                    • N Nimika

                      @SGaist Can I use serial ports to any user other than root?

                      mrjjM Offline
                      mrjjM Offline
                      mrjj
                      Lifetime Qt Champion
                      wrote on last edited by mrjj
                      #23

                      @Nimika
                      Hi
                      Any user can be granted access to /dev/X devices.
                      Often it is done via the dialout group as its already assigned to serial devices such as ttyS0 and
                      any user that is member of that group can use it.
                      so often
                      sudo adduser TheUserName dialout
                      and and reboot is all that is needed.
                      Adding user to group might have slightly different syntax on RH but concept and rights are 100% the same.:)
                      http://websistent.com/fix-serial-port-permission-denied-errors-linux/

                      N jsulmJ 2 Replies Last reply
                      0
                      • mrjjM mrjj

                        @Nimika
                        Hi
                        Any user can be granted access to /dev/X devices.
                        Often it is done via the dialout group as its already assigned to serial devices such as ttyS0 and
                        any user that is member of that group can use it.
                        so often
                        sudo adduser TheUserName dialout
                        and and reboot is all that is needed.
                        Adding user to group might have slightly different syntax on RH but concept and rights are 100% the same.:)
                        http://websistent.com/fix-serial-port-permission-denied-errors-linux/

                        N Offline
                        N Offline
                        Nimika
                        wrote on last edited by
                        #24

                        @mrjj Thanks let me try it.

                        1 Reply Last reply
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                        • mrjjM mrjj

                          @Nimika
                          Hi
                          Any user can be granted access to /dev/X devices.
                          Often it is done via the dialout group as its already assigned to serial devices such as ttyS0 and
                          any user that is member of that group can use it.
                          so often
                          sudo adduser TheUserName dialout
                          and and reboot is all that is needed.
                          Adding user to group might have slightly different syntax on RH but concept and rights are 100% the same.:)
                          http://websistent.com/fix-serial-port-permission-denied-errors-linux/

                          jsulmJ Offline
                          jsulmJ Offline
                          jsulm
                          Lifetime Qt Champion
                          wrote on last edited by
                          #25

                          @mrjj @Nimika Just a note: after adding currently logged on user to a group you do not have to reboot (its not Windows :-)) - just log out and log in again.

                          https://forum.qt.io/topic/113070/qt-code-of-conduct

                          N 1 Reply Last reply
                          0
                          • jsulmJ jsulm

                            @mrjj @Nimika Just a note: after adding currently logged on user to a group you do not have to reboot (its not Windows :-)) - just log out and log in again.

                            N Offline
                            N Offline
                            Nimika
                            wrote on last edited by
                            #26

                            @jsulm Thank you!!
                            But still in my case maybe RHEL is not allowing any other user to add in dialout group.

                            mrjjM jsulmJ 2 Replies Last reply
                            0
                            • N Nimika

                              @jsulm Thank you!!
                              But still in my case maybe RHEL is not allowing any other user to add in dialout group.

                              mrjjM Offline
                              mrjjM Offline
                              mrjj
                              Lifetime Qt Champion
                              wrote on last edited by
                              #27

                              @Nimika said in Serial Port configuration in RHEL:

                              RHEL is not allowing any other user to add in dialout group.

                              cant you just use sudo in front?

                              1 Reply Last reply
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                              • N Nimika

                                @jsulm Thank you!!
                                But still in my case maybe RHEL is not allowing any other user to add in dialout group.

                                jsulmJ Offline
                                jsulmJ Offline
                                jsulm
                                Lifetime Qt Champion
                                wrote on last edited by
                                #28

                                @Nimika RHEL works like any other Linux distribution. To add a user to a group you need to be root. You can either login as root, or just enter su in a terminal window enter your root password and then add the user to the group. su is used to become root in a shell (you need root password).
                                @mrjj I think on RHEL sudo is usually not used, so sudo will probably not work (as far as I know, I could be wrong as I use Ubuntu).

                                https://forum.qt.io/topic/113070/qt-code-of-conduct

                                N mrjjM 2 Replies Last reply
                                0
                                • jsulmJ jsulm

                                  @Nimika RHEL works like any other Linux distribution. To add a user to a group you need to be root. You can either login as root, or just enter su in a terminal window enter your root password and then add the user to the group. su is used to become root in a shell (you need root password).
                                  @mrjj I think on RHEL sudo is usually not used, so sudo will probably not work (as far as I know, I could be wrong as I use Ubuntu).

                                  N Offline
                                  N Offline
                                  Nimika
                                  wrote on last edited by
                                  #29

                                  @jsulm
                                  Yeah I did all possibilities which I think can be done on RHEL.
                                  By the way Thanks a lot for your all kind replies. :)

                                  jsulmJ 1 Reply Last reply
                                  0
                                  • N Nimika

                                    @jsulm
                                    Yeah I did all possibilities which I think can be done on RHEL.
                                    By the way Thanks a lot for your all kind replies. :)

                                    jsulmJ Offline
                                    jsulmJ Offline
                                    jsulm
                                    Lifetime Qt Champion
                                    wrote on last edited by
                                    #30

                                    @Nimika So, is your user now member of dialout group? You can check this executing "groups" command in a terminal (not as root but as the user who needs the access rights!). You can add a user to a group manually: open /etc/group file in an editor (as root), look for a line like "dialout:x:115:" and append user name at the end of that line.

                                    https://forum.qt.io/topic/113070/qt-code-of-conduct

                                    N 1 Reply Last reply
                                    0
                                    • SGaistS Offline
                                      SGaistS Offline
                                      SGaist
                                      Lifetime Qt Champion
                                      wrote on last edited by
                                      #31

                                      In addition to what my fellows already wrote, if you're not too found of manipulating your user setting with the command line, most of desktop environment (KDE, Gnome, etc.) provide user management software so you'll likely be able to add your user to the dialout group with them. They should ask for an admin password when required.

                                      Interested in AI ? www.idiap.ch
                                      Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                                      1 Reply Last reply
                                      1
                                      • jsulmJ jsulm

                                        @Nimika RHEL works like any other Linux distribution. To add a user to a group you need to be root. You can either login as root, or just enter su in a terminal window enter your root password and then add the user to the group. su is used to become root in a shell (you need root password).
                                        @mrjj I think on RHEL sudo is usually not used, so sudo will probably not work (as far as I know, I could be wrong as I use Ubuntu).

                                        mrjjM Offline
                                        mrjjM Offline
                                        mrjj
                                        Lifetime Qt Champion
                                        wrote on last edited by
                                        #32

                                        @jsulm
                                        Oh, you are right. it might not be set up at all
                                        https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux_OpenStack_Platform/2/html/Getting_Started_Guide/ch02s03.html
                                        so su is the way to go.

                                        1 Reply Last reply
                                        1
                                        • jsulmJ jsulm

                                          @Nimika So, is your user now member of dialout group? You can check this executing "groups" command in a terminal (not as root but as the user who needs the access rights!). You can add a user to a group manually: open /etc/group file in an editor (as root), look for a line like "dialout:x:115:" and append user name at the end of that line.

                                          N Offline
                                          N Offline
                                          Nimika
                                          wrote on last edited by
                                          #33

                                          @jsulm
                                          No my user is not the member because its not working in the dialout group.
                                          I did by editing to the group file as well. Whenever I am in my root and adding the user to the group it is showing that this user is already have the group.

                                          @SGaist
                                          which management software you are talking about??

                                          mrjjM jsulmJ 2 Replies Last reply
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