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    • cyperghostC
      cyperghost
      last edited by cyperghost

      @meleu
      About the nerdy stuff :)
      https://retropie.org.uk/forum/topic/11750/mausberry-shutdown-script-doesn-t-save-metadata/122

      Why you prefer [[ -n ]] rather if [ "$pid" ]
      The value in your bracket is always true because runcommand.info will be available and contains values of last emucall even after you go back to ES view (caroussel-mode) and so you try to kill an emulator that is not active and you activate sleep timer.

      I extract PID and check if the PID is "true" if not then the value is untrue and so I'm pretty sure there is no emulator actually running and proceed with quitting ES. I'm also sure that 12 seconds aren't needed :) Maybe for a Pi 1/0 :)

      See my garbage PID script

      PS You should dive into the experience of GPIOs :)

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      • cyperghostC
        cyperghost @meleu
        last edited by

        @meleu said in shell scripting topic:

        Look this:

        [prompt]$ pkill -f inexistent_process && echo blablabla
        [prompt]$ pkill -f inexistent_process ; echo $?
        1
        [prompt]$ 
        

        Got it?

        Yes for sure.... got it!
        So the && addition breaks if one condition is not true!
        Okay got it :) But I prefer not to use pkill if it is not needed. I would always obtain PID via pgrep and then use kill-command. I think that is just philosophic

        Thank you very much

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        • meleuM
          meleu
          last edited by

          @cyperghost said in shell scripting topic:

          Why you prefer [[ -n ]] rather if [ "$pid" ]

          The initial reason was because I like to follow RetroPie's Shell Style Guide, but there's a more reasonable answer here.

          The value in your bracket is always true because runcommand.info will be available and contains values of last emucall

          I think you already noticed that this isn't true, right?

          you try to kill an emulator that is not active and you activate sleep timer.

          It's also not true.

          This code:

          command1 && command2 && command3
          

          is equivalent to

          if command1; then
             if command2; then
                command3
             fi
          fi
          

          The use of && and || is useful when you have to test something and then execute a single command.

          More info about this syntax here: http://mywiki.wooledge.org/BashGuide/TestsAndConditionals#Control_Operators_.28.26.26_and_.7C.7C.29

          Cheers!

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          • cyperghostC
            cyperghost @meleu
            last edited by

            @cyperghost said in shell scripting topic:

            Yes for sure.... got it!
            So the && addition breaks if one condition is not true!

            I think I answered myself but you explained it now more didactic

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            • meleuM
              meleu
              last edited by

              @cyperghost let's get back to the nerdy topic :-)

              you said in Mausberry Shutdown Script Doesn't Save Metadata:

              #!/bin/bash
              emucall=$(sed -n 4p /dev/shm/runcommand.info)
              emupid=${emucall#* }
              pos=$(expr ${#emucall} - ${#emupid})
              $emupid=$(pgrep -f -n ${emucall:0:$pos})
              kill $emupid
              

              The code sniplet above should still do the job as it was introduced for a few days and was titled "complex" - it isn't ;)
              It's robust string operation and searches for first occurence for space and then kills the latest process :)

              Look this example using your approach:

              [PROMPT]$ # look how RetroPie calls ScummVM
              [PROMPT]$ sed -n 4p /dev/shm/runcommand.info 
              bash /home/meleu/RetroPie/roms/scummvm/+Start\ ScummVM.sh "ft"
              [PROMPT]$ emucall=$(sed -n 4p /dev/shm/runcommand.info)
              [PROMPT]$ emupid=${emucall#* }
              [PROMPT]$ pos=$(expr ${#emucall} - ${#emupid})
              [PROMPT]$ echo "${emucall:0:$pos}"
              bash 
              

              Now with the other approach:

              [PROMPT]$ emucall=$(sed -n 4p /dev/shm/runcommand.info)
              [PROMPT]$ echo "${emucall%% *}"
              bash
              

              See? Exactly the same result.

              But the bug I reported isn't about this nerdy stuff... I'll expand on the next post... :-)

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              • cyperghostC
                cyperghost @meleu
                last edited by cyperghost

                @meleu Yes...
                But I also wrote... to use the -n switch for pkill or pgrep then only the latests process will be killed or PID obtained and all is good :)

                My approch about the string operation is following
                If you search for the first occurence of " /" then you can be sure you got the name of the running process. I think I must take a deeper look to sed or even awk scripting.

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                • meleuM
                  meleu
                  last edited by meleu

                  @cyperghost the bug I reported here happens because the pattern for pgrep -f and pkill -f is a regular expression, and that 4th line on runcommand.info is not a regex and can have characters with special meanings in a regex context.

                  In my ScummVM example:

                  bash /home/meleu/RetroPie/roms/scummvm/+Start\ ScummVM.sh "ft"
                                                         ^
                                                         |
                                 This plus '+' sign is "confusing" pgrep/pkill
                  
                  

                  So this is the solution I've found (note: a dot . in a RegEx context means "any character or nothing"):

                  emu_command="$(sed -n 4p /dev/shm/runcommand.info | tr -d '\\"' | tr '^$[]*.()|+?{}' '.')"
                  # explaining the crazy pipes above:
                  # 1. get 4th line of runcommand.info (aka "emulator command")
                  # 2. delete backslash '\' character
                  # 3. replace every character that has a special meaning in a regex context with a dot '.'
                  
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                  • meleuM
                    meleu @cyperghost
                    last edited by

                    @cyperghost said in shell scripting topic:

                    But I also wrote... to use the -n switch for pkill or pgrep then only the latests process will be killed or PID obtained and all is good :)

                    In the ScummVM example your approach would return the last bash process. I can't see how you can assure that the most recent bash call is the ScummVM caller one.

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                    • cyperghostC
                      cyperghost @meleu
                      last edited by cyperghost

                      @meleu Okay then I was on the wrong way. I thought pkill killed ALL bash calls because it just extracted "bash" so my intentention was to kill only latest bash call and therefore use the coded bash sniplet
                      Sorry I didn't test with SCUMMVM and so did not realize that there is a problem with the RegEx call :)

                      I'm really glad you find out!


                      EDIT:

                      About latest bash. No that can't be 100% true but 99%
                      Is SCUMMVM the only caveeat?

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                      • cyperghostC
                        cyperghost
                        last edited by cyperghost

                        @meleu Thank you in advance :) I know you want 100% working solutions and I'm thankfull for your immediate help :) So I see ... when is version 1.7 ready?
                        It's unbelievable how much energy you invest in such small sniplets.

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                        • meleuM
                          meleu @cyperghost
                          last edited by

                          @cyperghost

                          About latest bash. No that can't be 100% true but 99%

                          As we already realized before, the runcommand.info file persists even after the "emulator" ends. In this case it would fail 100% of the times (we don't want to go with that approach deleting the runcommand.info because we know it's useful for debugging, OK?). :-)

                          Is SCUMMVM the only caveeat?

                          Any "emulator" that runcommand.sh calls via shell script. I didn't test but I think that many of those on "ports" are called this way.

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                          • cyperghostC
                            cyperghost @meleu
                            last edited by cyperghost

                            @meleu No... (Zdoom, -lr-prboom, lr-tyrquake) there was no problem :)

                            As we already realized before, the runcommand.info file persists even after the "emulator" ends. In this case it would fail 100% of the times (we don't want to go with that approach deleting the runcommand.info because we know it's useful for debugging, OK?). :-)

                            1:0

                            So again - I'm looking forward in v1.7
                            two versions

                            1. Mausberry shutdown script without inotify
                            2. Mausberry shutdown script with inotify

                            About inotify we have to talk later :)

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                            • meleuM
                              meleu @cyperghost
                              last edited by

                              @cyperghost

                              So again - I'm looking forward in v1.7
                              two versions

                              1. Mausberry shutdown script without inotify
                              2. Mausberry shutdown script with inotify

                              I would like to emphasize the difference between versions this way:

                              1. Shutdown script checking for a change in that file every single second.
                              2. Shutdown script that does nothing until that file changes.

                              :-)

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                              • cyperghostC
                                cyperghost
                                last edited by cyperghost

                                @meleu I will raise Garbage PID detector to v1.1 with your RegEx findings.
                                thx mate

                                @meleu PID detector 1.1 is ready. Sorry I used emupid instead of emu_command
                                It now works 100% flawless ...

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                                • cyperghostC
                                  cyperghost
                                  last edited by

                                  @meleu
                                  I pushed the mausberry shutdown script to 1.55 - all kudos to you.
                                  But I want to avoid different usecased. Because some use 1.5 now.
                                  So I think it doesn't matter if there is a v1.7 with better coding style or a v1.55 with more if-then clauses.
                                  All contain your genoius RegEx sniplet that will work in all cases! I hope it is okay for you. In the sake for the best user experience we can give.

                                  meleuM 1 Reply Last reply Reply Quote 0
                                  • meleuM
                                    meleu @cyperghost
                                    last edited by

                                    @cyperghost said in shell scripting topic:

                                    I hope it is okay for you.

                                    C'mon man! Every line of code I post in this forum can be considered public domain. ;-)

                                    Use it the way you want!

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                                    • cyperghostC
                                      cyperghost @meleu
                                      last edited by

                                      @meleu okay PD-meleu

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                                      • meleuM
                                        meleu @cyperghost
                                        last edited by

                                        @cyperghost said in Mausberry Shutdown Script Doesn't Save Metadata:

                                        I think so, but I'm pretty sure that your solution (ScummVM fix) is already in usage by @hansolo77

                                        Your posted script is still using this:

                                        emupid="$(pgrep -f "${emupid%% *}")"
                                        

                                        Which gets only bash on ScumVM case. Maybe you want to change it to v1.56 and use

                                        emupid="$(pgrep -f "$emupid")"
                                        
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                                        • cyperghostC
                                          cyperghost @meleu
                                          last edited by

                                          @meleu Thx my friend

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                                          • cyperghostC
                                            cyperghost @meleu
                                            last edited by cyperghost

                                            @meleu About the inotify thing.
                                            Do you have any clue why the GPIO signal is not detected? At first it works only if you have root access - but I'm pretty sure you already know. As far as I looked to v 1.6 of your code it should work without any problem.

                                            If there are any issues you can try to use GPIO control

                                            If you watch Pin26 for a switch via GPIO control just place file 26 (without .sh!) to /etc/gpio-scripts/ and give the echo 1 > command in this file.

                                            26

                                            #!/bin/bash
                                            #this is the GPIO pin connected to the lead on switch labeled OUT
                                            GPIOpin1=23
                                            echo "1" > /sys/class/gpio/gpio$GPIOpin1/value
                                            meleuM 1 Reply Last reply Reply Quote 0
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