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    Please do not post a support request without first reading and following the advice in https://retropie.org.uk/forum/topic/3/read-this-first

    [Solved] How to bind a shell command to a hotkey? (raspi2png)

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    • ClydeC
      Clyde @hermit
      last edited by Clyde

      @hermit My dirty hack solution after some reading:

      raspi2png --pngname $(basename -s .zip `ps a|grep RetroPie/roms/|head -1|sed -e 's/ /_/g'|awk '{ print $NF }'|sed 's/\\\//g'`).png
      

      I inserted the command sed -e 's/ /_/g' before awk to convert any whitespace to an underscore, and a sed 's/\\\//g' after awk to remove any \ which the Linux shell uses to mark special characters like whitespaces,', (, ) etc.

      I did it this way because awk seems to have problems with whitespaces (thus sed removes them beforehand), but also needs the backslash before special characters (thus sed removes them only afterwards).

      I sometimes can't let unsolved problems just go … although I now have to hurry cleaning up my flat before going to a party. 😌

      edit: See @mitu's optimised version with whitespace-passthrough and multiple filename extensions support here.

      1 Reply Last reply Reply Quote 0
      • H
        hermit
        last edited by

        @Clyde perfect :) tested with both snes and amiga :) Thanks a lot :)

        thank you all :)

        1 Reply Last reply Reply Quote 0
        • ClydeC
          Clyde
          last edited by Clyde

          Okay, I finally got around working on this. Here's my tested solution:

          1. Install triggerhappy:
          sudo apt install triggerhappy
          
          1. Change its service configuration file using sed to run it as user pi for writing permissions in that user's $HOME directory (optional, but needed for the example below):
          sudo sed -i -e 's/nobody/pi/' /etc/systemd/system/multi-user.target.wants/triggerhappy.service
          
          1. Use thd to find the code of the key you want to connect a shell command to:
          thd --dump /dev/input/*      # exit with CTRL+C
          
          1. Put the code and the desired shell command into a fittingly named file in the directory /etc/triggerhappy/triggers.d/
            Example: Running the raspi2png command from above on the press of "Print Screen", using the config file /etc/triggerhappy/triggers.d/raspi2png.conf:
          KEY_SYSRQ 1 raspi2png --pngname "/home/pi/$(ps a | grep RetroPie/roms | awk -F "/" 'NR==1 { print $NF }' | sed 's/\.[^.]*$//g; s/\\//g')"-$(date +%Y.%m.%d-%H.%M.%S).png
          
          • KEY_SYSRQ is the code for the "Print Screen" key on most standard keyboards.
          • "1" = pressing the key, "2" = holding the key down, "0" = releasing the key
          • The rest is the command or script to run in this event. You may have to add the path to your raspi2png if it's not in your shell's search path like /home/pi/bin is for example.
          • Optional: Put the command in a shell script and run the script from the .conf file. See @roslofs post below. This may be advisable for multiple commands or if you change them from time to time, sparing you the reloading of the demon (see #4).
          1. Reload the service to apply the changes:
          sudo systemctl daemon-reload                 # reload the changes in triggerhappy.service
          sudo systemctl restart triggerhappy.service  # reload the changes in /etc/triggerhappy/triggers.d/
          

          Now, in the above example, pressing "Print Screen" should save a screenshot named after the currently running ROM file in the directory /home/pi/.

          Comments, test results, corrections, and enhancements are welcome. :)

          edit: You can check the status and any error messages of the triggerhappy daemon with the command sudo systemctl status triggerhappy.service.
          edit 2: Changed the raspi2png command to @mitu's optimised version.
          edit 3: Added @mitu's correction and @roslofs script variant.

          mituM 1 Reply Last reply Reply Quote 3
          • ClydeC
            Clyde
            last edited by

            Credits go to @mitu, @Zigurana, @Djon, and @Headrush69 for their groundwork in https://retropie.org.uk/forum/topic/2377/control-volume-through-retroarch-with-keyboard and https://retropie.org.uk/forum/topic/18133/triggerhappy-daemon-thd-doesn-t-work-on-my-pi-running-retropie-help.

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            • mituM
              mitu Global Moderator @Clyde
              last edited by mitu

              @Clyde Hey, you got it working - great stuff !

              Now, the suggestions :) :

              • You can probably replace the long line of
              `ps a|grep RetroPie/roms/|head -1|sed -e 's/ /_/g'|awk '{ print $NF }'|sed 's/\\\//g'`
              

              with something like

              ps a | grep RetroPie/roms | head -1 | awk -F "/" '{ print $NF }'
              

              This will get you the last path segment (which can be a file or folder) from the line containing the ROM path.

              EDIT: this will also preserve whitespaces in the filename, so it's not a drop-in replacement for the original command.

              • You're assuming the ROM is a .zip, but that not might be the case. Can't think of a simple and elegant way of dealing with this but I have an idea.
              ClydeC 1 Reply Last reply Reply Quote 2
              • ClydeC
                Clyde @mitu
                last edited by Clyde

                @mitu I already played around with awk -F but I got no good results.

                raspi2png --pngname /home/pi/$(basename -s .zip `ps a | grep RetroPie/roms/ | head -1 | awk -F "/" '{ print $NF }'`).png
                

                will save a file called 7th\, whereas my command will save 7th_Saga,_The_(USA).png.

                edit: I gave up on preserving the whitespaces. :)
                edit 2: Have to leave for the gym now. I'm curious about your idea about the rom's filename extension.

                1 Reply Last reply Reply Quote 0
                • mituM
                  mitu Global Moderator
                  last edited by mitu

                  If you don't quote your argument, spaces will surely be a problem. Anyway, here it is what I got so far.

                  raspi2png --pngname "$(ps a | grep RetroPie/roms | awk -F "/" 'NR==1 { print $NF }' | sed 's/\.[^.]*$//g')"-$(date +%Y.%m.%d-%H.%M.%S).png
                  

                  This should work with spaces, regardless of extension, and adds a timestamp at the end. If you'd like to keep the date format the way RetroArch does it, you can use:

                  raspi2png --pngname "$(ps a | grep RetroPie/roms | awk -F "/" 'NR==1 { print $NF }' | sed 's/\.[^.]*$//g')"-$(date +%y%m%d-%H%M%S).png
                  

                  Now, the RetroArch reference got me thinking, so I checked and you can tell RA to take a screenshot with the Network control interface - https://docs.libretro.com/tech/network-control-interface/. Assuming you got RA configured to start this interface (I don't think it's enabled by default, I just have it for the power off/reset buttons), the command to take a screenshot can be just

                  echo -n "SCREENSHOT" | nc -u -w1 127.0.0.1 55355
                  

                  and a screenshot would be saved in ~/.config/retroarch/screenshots (a.k.a. /opt/retropie/configs/all/retroarch/screenshots or \\retropie\configs\all\retroarch\screenshots). You'll need netcat installed to provide the nc command.

                  ClydeC 1 Reply Last reply Reply Quote 1
                  • ClydeC
                    Clyde @mitu
                    last edited by

                    @mitu said in How to bind a shell command to a hotkey? (raspi2png):

                    If you don't quote your argument, spaces will surely be a problem. Anyway, here it is what I got so far.

                    raspi2png --pngname "$(ps a | grep RetroPie/roms | awk -F "/" 'NR==1 { print $NF }' | sed 's/\.[^.]*$//g')"-$(date +%Y.%m.%d-%H.%M.%S).png
                    

                    This still won't get rid of the backslashes, e.g. creating Super\ Mario\ Bros.\ \(2P\ Hack\)-2019.02.23-18.10.44.png. But it does work with the .nes extension of this rom, thanks!

                    raspi2png --pngname "$(ps a | grep RetroPie/roms | awk -F "/" 'NR==1 { print $NF }' | sed 's/\.[^.]*$//g')"-$(date +%y%m%d-%H%M%S).png
                    

                    Same here: Super\ Mario\ Bros.\ \(2P\ Hack\)-190223-181049.png

                    echo -n "SCREENSHOT" | nc -u -w1 127.0.0.1 55355
                    

                    Works like a charm, thanks again for this alternative!

                    1 Reply Last reply Reply Quote 0
                    • mituM
                      mitu Global Moderator
                      last edited by mitu

                      Yes, the dreaded \, forgot about them - I was testing with an emulator started. This can be fixed taking the sed command from your initial line:

                      raspi2png --pngname "$(ps a | grep RetroPie/roms | awk -F "/" 'NR==1 { print $NF }' | sed 's/\.[^.]*$//g; s#\\##g')"-$(date +%Y.%m.%d-%H.%M.%S).png
                      

                      E.T.\ The\ Extra-Terrestrial\ \(1982\)\ \(Atari\)\ \(PAL\)\ \[\!\]-2019.02.23-17.20.15.png becomes E.T. The Extra-Terrestrial (1982) (Atari) (PAL) [!]-2019.02.23-17.25.43.png

                      ClydeC 2 Replies Last reply Reply Quote 1
                      • ClydeC
                        Clyde @mitu
                        last edited by

                        @mitu To answer in German: Wunderbar! 😄

                        1 Reply Last reply Reply Quote 0
                        • ClydeC
                          Clyde @mitu
                          last edited by Clyde

                          @mitu said in How to bind a shell command to a hotkey? (raspi2png):

                          aspi2png --pngname "$(ps a | grep RetroPie/roms | awk -F "/" 'NR==1 { print $NF }' | sed 's/\.[^.]*$//g; s#\\##g')"-$(date +%Y.%m.%d-%H.%M.%S).png
                          

                          You might want to change that to raspi2png with an "r". 😉

                          edit: Aaaand … I saw your post changing while I was waiting for this post to appear. 😆

                          mituM 1 Reply Last reply Reply Quote 0
                          • mituM
                            mitu Global Moderator @Clyde
                            last edited by mitu

                            @Clyde I already did :). Anyway, I think you should add a reference to your solution post to your 1st post, so people can find it without reading to the whole topic.
                            Now the challenge is to find the equivalent of raspi2png for other platforms (Odroid, Pc).

                            ClydeC 2 Replies Last reply Reply Quote 0
                            • ClydeC
                              Clyde @mitu
                              last edited by Clyde

                              @mitu Did you read my mind? I just did that. 😱 😄

                              edit: Er … sorry, I didn't do that, but added a reference of your raspi2png solution to my first one. Adding the reference that you meant now. 😳

                              1 Reply Last reply Reply Quote 1
                              • ClydeC
                                Clyde @mitu
                                last edited by

                                @mitu Done, along with "[Solved]" in the title and my How-To updated with your raspi2png line.

                                I love communities like this for such constructive synergy. 😊

                                1 Reply Last reply Reply Quote 0
                                • roslofR
                                  roslof
                                  last edited by roslof

                                  Love this thread, but I may need a smidgen more help to get this to work.

                                  I followed Clyde's guide to the letter, but after pressing the defined key, entering sudo systemctl status triggerhappy.server yields:

                                  Feb 23 19:01:19 retropie thd[2523]: Executing trigger action: raspi2png --pngname "/home/pi/$(ps a | grep RetroPie/roms | awk -F "/" 'NR==1 { print $NF }' | sed 's/.[^.]*$//g; s <---abruptly ends
                                  Feb 23 19:01:19 retropie thd[2523]: sh: 1: Syntax error: Unterminated quoted string

                                  Looks like it's cutting off the command line... No idea why. It looks fine in the config file. Actually, I just noticed that the line is being cut after EXACTLY 128 characters... So I wager I'm experiencing some character line limit that y'all are not.
                                  Edit: It turned out the character limit was a red herring and not the cause.

                                  FWIW, if I copy the same information from Step 4 into bash (removing KEY_SYSRQ 1) it works fine, and raspi2png takes the shot and the output file is named correctly. So the syntax as provided by Clyde (via Mitu) is definitely correct.

                                  I'm only having trouble w/triggerhappy truncating the line from the config file in triggers.d.

                                  Any advice?

                                  mituM 1 Reply Last reply Reply Quote 0
                                  • mituM
                                    mitu Global Moderator @roslof
                                    last edited by

                                    @roslof If you post the contents of the /etc/triggerhappy/triggers.d/raspi2png.conf we may be able to spot any errors.

                                    roslofR 1 Reply Last reply Reply Quote 0
                                    • roslofR
                                      roslof @mitu
                                      last edited by roslof

                                      @mitu You bet, but it really is the same as step 4 above, and it definitely works at a bash prompt:

                                      KEY_SYSRQ 1 raspi2png --pngname "/home/pi/$(ps a | grep RetroPie/roms | awk -F "/" 'NR==1 { print $NF }' | sed 's/\.[^.]*$//g; s#\\##g')"-$(date +%Y.%m.%d-%H.%M.%S).png
                                      

                                      Syntax-wise, this is good. It just gets cropped during parsing after the 128th character.

                                      I did, however, figure out a work-around. I just created a separate script/.sh to run raspi2png w/all the parameters. Then I just called the script from raspi2png.conf ;-)

                                      My work-around:

                                      Newly added /etc/triggerhappy/triggers.d/run-raspi2png.sh ensure executable perm flag is set

                                      raspi2png --pngname "/home/pi/$(ps a | grep RetroPie/roms | awk -F "/" 'NR==1 { print $NF }' | sed 's/\.[^.]*$//g; s#\\##g')"-$(date +%Y.%m.%d-%H.%M.%S).png
                                      

                                      Revised /etc/triggerhappy/triggers.d/raspi2png.conf

                                      KEY_SYSRQ 1 /etc/triggerhappy/triggers.d/run-raspi2png.sh
                                      

                                      Edit Note: Previously posted a line that used nohup, which was non-essential. For the curious, it was: KEY_SYSRQ 1 nohup /etc/triggerhappy/triggers.d/run-raspi2png.sh 0<&- &>/dev/null &

                                      I have to say, the command-line arguments you and Clyde created are super-creative. I never would have imagined a screen capture with proper naming, and a solution for ANY emulator, including non-Retroarch. Great work, guys!

                                      roslofR ClydeC 2 Replies Last reply Reply Quote 2
                                      • roslofR
                                        roslof @roslof
                                        last edited by roslof

                                        removed post based on insights from mitu

                                        mituM 1 Reply Last reply Reply Quote 0
                                        • mituM
                                          mitu Global Moderator @roslof
                                          last edited by

                                          @roslof That's not necessary on Raspbian (and RetroPie) since the pi user is already a member of the video group and has access to /dev/vchiq. This kind of advice (make the /dev/whatever writable to anyone) it's just encouraging bad practice - don't do it, instead make sure your user is in the correct group.

                                          roslofR 1 Reply Last reply Reply Quote 0
                                          • roslofR
                                            roslof @mitu
                                            last edited by

                                            @mitu Helpful. I'll edit the post. Unclear why I was in this state.

                                            mituM 1 Reply Last reply Reply Quote 0
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