Issue displaying anything from shell script before launching an app from Gmenu2x launcher

[ploupipoulpi]

Long story short, I am trying to launch LGPT Tracker with a script for color theme selection. (Working on the CFW1.3 on a V90)
I can already run LGPT Tracker fine. But when I try launching it through a themeselection.sh, I'm having issues.
I added the link to the script in the applications folder in sections.

title=LGPTSEL
description=Little Tracker
exec=/mnt/apps/XLGPT/themeselection.sh
clock=702

It works, but if it gets my keystrokes on the buttons and runs lgpt.elf with the appropriate parameters when I hit start, I only get a black screen until then and I can't seem to get anything to be displayed before lgpt starts.
After that lgpt runs properly.

Overall I could try any script and wouldn't seem to get anything on screen.

Can anyone help me figure out what I am getting wrong? I am in no way a developer but after reading most of the docs on this firmware and on gmenu2x I could find here and there, I feel quite stupid.

Thanks in advance, I hope I'm in the right place for this question.

[Apaczer]

I susspect you want smth to be printed out to tty terminal (not sure cuz u didn't show us the script), but you should know that any child process run by gmenu2x will have any stdout/stderr sent to /dev/null (the same applies to 1.3.3).

[ploupipoulpi]

Hi thanks for your answer, your assumption was correct, I didn't think a script would add anything to the discussion since all I could get was a black screen regardless.

I since had found this mention in the launch.sh that runs ffplay, as well as in a cfw changelog.
https://github.com/MiyooCFW/buildroot/blob/8c3d70a6f40b3387030ff50c51f9a7309b00b5c2/board/miyoo/main/apps/ffmpeg/ffplay_launch.sh#L19

Anyway thanks for confirming about the stdout.

To be fair, I'm testing several use cases of GPT4o for my day job and this was an ideal candidate for experiments.

I finally got to a dirty functional script that does display what I want and works.
I can now get to making something that looks better and is more practical for my use case. My first issue was getting something on screen before making anything nice.

In any case, here's the first fully functional script, feel free to tell me everything that's bad about it. A robot made it so I won't take any offense at all (btw, I know these color themes are eye cancer, I just wanted to really see the difference when testing).

#!/bin/sh

# Function to display the menu
display_menu() {
    echo -e "\033[H\033[J" > /dev/tty1  # Clear the screen
    echo "Select an option using the arrow keys and press Enter:" > /dev/tty1
    echo > /dev/tty1
    if [ "$selected" = "blue" ]; then
        echo "  > Blue" > /dev/tty1
    else
        echo "    Blue" > /dev/tty1
    fi
    if [ "$selected" = "red" ]; then
        echo "  > Red" > /dev/tty1
    else
        echo "    Red" > /dev/tty1
    fi
    if [ "$selected" = "candy" ]; then
        echo "  > Candy" > /dev/tty1
    else
        echo "    Candy" > /dev/tty1
    fi
}

# Initial selected option
selected="blue"

# Display the menu for the first time
display_menu

while true; do
    read -n 1 -s key
    case "$key" in
        $'\x1b')
            read -n 2 -s key
            case "$key" in
                '[A') # Up arrow
                    if [ "$selected" = "red" ]; then
                        selected="blue"
                    elif [ "$selected" = "candy" ]; then
                        selected="red"
                    fi
                    ;;
                '[B') # Down arrow
                    if [ "$selected" = "blue" ]; then
                        selected="red"
                    elif [ "$selected" = "red" ]; then
                        selected="candy"
                    fi
                    ;;
            esac
            ;;
        '') # Enter key
            break
            ;;
    esac
    display_menu
done

# Run the corresponding command based on the selected option
case "$selected" in
    "blue")
        ./lgpt.elf -BACKGROUND=0000FF -FOREGROUND=330033 -HICOLOR1=FF66FF -HICOLOR2=990099
        ;;
    "red")
        ./lgpt.elf -BACKGROUND=FF0000 -FOREGROUND=330033 -HICOLOR1=FF66FF -HICOLOR2=990099
        ;;
    "candy")
        ./lgpt.elf -BACKGROUND=FF00FF -FOREGROUND=330033 -HICOLOR1=FF66FF -HICOLOR2=990099
        ;;
esac

Thanks again for your help!
If I get the nasty robot to make something that looks good I'll probably come around to post it here.

It would be nice if someone could add a functional version of LGPT in an user friendly manner (I had to get it from a 16gig image of a modified CFW that booted right in LGPT - from a guy who did a not so detailed video about the process). All the same, if you know of a nice place where to find the most recent LGPT build to run on the v90, let me know!

[Apaczer]

feel free to tell me everything that's bad about it. A robot made it

Foremost you should make sure it is POSIX compliant (not necessary but may protect from many suppries) and can be run within busybox's ash (the one u call by adding #!/bin/sh), to perform basic tests u could use shellcheck via CLI with shellcheck --shell=sh <script_name> or through VScode plugin. Looks like read -n option can't be accesed that way, but works on our busybox version so in theory there shouldn't be big issues, also check this method for hacking tty: MiyooCFW/buildroot#55 (comment)

It would be nice if someone could add a functional version of LGPT

There are Bittboy builds in https://github.com/djdiskmachine/LittleGPTracker/releases also smbd tested it on V90 (see issues
there), so they may bring back support for this platform.

[Apaczer]

Never used macOS myself, but one of our team members and others had succes with https://openmtp.ganeshrvel.com/ as well with official android file transfer drivers (can't find them currently, deprecated?). Not sure if they work on all OS versions, it would be the best if you refer to documentation there or ask authors/devs of mentioned drivers.

[ploupipoulpi]

Thanks, I thought it worked but not really.
It almost works, I can detect the device, read the contents of the SD, but cannot write on it, whether with openmtp on the mac, or on a linux laptop, I get libmtp error "Could not send object info", but I can copy things from the sd card just fine.

I have tried 3 computers, 4 cables... either I missed something obvious, or there's something else.

[ploupipoulpi]

Even when I try opening the SD card directly from my linux machine, I see the MAIN partition, and the rootfs and BOOT, I can read the main, but not write. I get permission denied. I kinda tried everything I could think of.
Maybe I'll flash another sd another day and see if it works.

[ploupipoulpi]

Forget what I said, I flashed a new sd card and it works with openmtp.
Thanks a lot!

[Apaczer]

I'm glad u sorted it out, and about permission issues - there may be smth to be done here see: MiyooCFW/buildroot#98 . Didn't have much time to test it under linux, but I already see different perm. for directories/files in MAIN partition which is wrong I believe...
Will be flashing Debian to my older machine for better UNIX alike support