shell scripting topic

cyperghost

@meleu Yes but for the sake of coding style

choice=$(dialog --command1 --command2 --menulist \
        1 Option 1 \
        2 Option 2 \
        redirection to ....)

is better coded in this script menu example ;)

dialogcmd=(dialog --command1 --command2 --menu)
dialogoptions=("1" "Option 1" "2" "Option 2")
choice=$("${dialogcmd[@]}" "${dialogoptions[@]}" redirection to)

And it will be much easier for bug hunting. Because structur here is clear. And this was my intention to bring this script module into game.
dialogcmd sets the structure of how the menu will looks like as array
dialogoptions is the data array for selection
and now with choice you put cmd and options together.

And I think this is a good example of clean coding ;)
Of course @lilbud will choose his own flavour later

lilbud

@meleu @cyperghost Here is my plan for the script: https://ghostbin.com/paste/6bbsa

not much in the way of code since I don't have a way to write/test it on my school computer.

hiulit

Hi there!

I've created my first shell script and I'd like your opinion, codewise.
It's a script to install some extras for RetroPie themes (icons, splashscreens and launching images).

The code is here: https://github.com/hiulit/es-theme-extras/blob/master/es-theme-extras.sh

I've created a post on this forum https://retropie.org.uk/forum/topic/13344/extras-for-retropie-themes-icons-splashscreens-and-launching-images-es_theme_extras-shell-script You can check it out to see more details.

Thanks! :)

meleu

@hiulit I saw that post. That's a pretty cool idea. I'm just a little busy with RL stuff, but I'll take a look at that soon. ;-)

hiulit

@meleu I'm glad you think it's a good idea! :D I think so too, but it would need every theme creator to get involved. We'll see if more people find it useful.

cyperghost

@hiulit Welcome on board ;)

hiulit

@cyperghost Thanks! :)

lostless

Just to continue this discussion. The kill run command program portion of shutdown script no longer works with retroarch in the most latest update from yesterday. Raspian files updated as well. It works with kodi. I have no other apps other than retroarch or kodi to test on. But this happened on 2 pi’s of mine so it last not a config i messes up.

So in essence. If in ES, shuts down fine. If in kodi, it exits to ES and then shuts down. If in retroarch, it just shuts down without saving meta data. Using the kill portion as a exit button. Nothing happens in retroarch, but kodi does exit.

FlashPC

Hi guys, this is only a hypothetical question. Is it possible to reset the order of the joysticks on the raspberry pi from the command line without rebooting.

As far as I know udev takes care of the js ordering. Yet emulators like Daphne only uses js0.

So can it be done where the script takes a snapshot of the udev js order, then asks you which usb device to use, then organise the list to have your desired device use the js0 slot and disable the rest. Then on the emulator exit return the udev js order to what it was.

meleu

@FlashPC You don't need to reboot to change the js* order. I think that changing the plugs is enough.

I don't know any way to set a joystick to be the js0 "on-the-fly" (keeping all of them connected). I've read something about using udev rules to set a specific controller to be the js0, but I'm afraid it isn't possible to change it on-the-fly.

By the way, I've wrote a script to let the user choose which controller to use for RetroArch players 1-4, but it works only for RetroArch emulators/cores.

FlashPC

@meleu the retroarch joystick selector is sweet, and it works great with the retroarch cores.

I did read somewhere that it might be possible to kill the udev process, and change the udev rules but that was using red hat linux I think....

meleu

@cyperghost let's bring this to our nerdy thread :-)

@cyperghost said in Hide systems/consoles and only show "all games" section:

@EctoOne you're right. Using that symbolic link approach and removing the unwanted systems from es_systems.cfg would work too (I think).

Hmmm.... Are you sure? Where are the runcommand calls stored? Or do you create them by your custom control script?

The script I made to launch the emulator detects the system in ROM's path. The script is quite small, then I'm pasting it here:

#!/usr/bin/env bash
# runcustom.sh

# testing if it's a symbolic link
if [[ ! -L "$1" ]]; then
    dialog --msgbox "ERROR: \"$1\" is not a symbolic link." 0 0
    exit 1
fi

# getting the name of the file that the symbolic link points to
rom="$(readlink "$1")"

# getting the system based on the folder the rom is stored
system="$(echo "$rom" | sed 's|\(.*/RetroPie/roms/[^/]*\).*|\1|' | xargs basename)"

# now launch runcommand normally
/opt/retropie/supplementary/runcommand/runcommand.sh 0 _SYS_ "$system" "$rom"

More details in the original post: https://retropie.org.uk/forum/topic/10849/create-a-custom-es-system-able-to-launch-games-for-many-systems

cyperghost

@meleu Yes, last line is the call command like es_systems.cfg
I'm not aware of the linking method but this should work in 99% of all time.
The method I used is to extract the whole command calls of es_systems in one file.

But both methods are hacks.... So your suggestions is really the best - use the all systems method. Maybe if the kios-mode is implented ES is supervisor-save and there is no need for such efforts :)

meleu

@hiulit Another tip for your fun-facts-script project:

Declare a variable for fun_facts.txt, set the file's full path to the variable, and use the variable when you need to reference that file.

It avoids some No such file or directory errors when you invoke the script from another directory.

Example:

~/src/funfacts $ ls
es-fun-facts-splashscreens.sh*  fun_facts.txt
~/src/funfacts $ ./es-fun-facts-splashscreens.sh
Mario first appeared in 1981 as the playable character in Nintendo's arcade game Donkey Kong. However, he was a carpenter known only as Jumpman
~/src/funfacts $ # THE SCRIPT RUNS FINE
~/src/funfacts $ cd ..
~/src $ ./funfacts/es-fun-facts-splashscreens.sh
shuf: fun_facts.txt: No such file or directory

EDIT

This is the best method I've found to detect the script's dir:

readonly SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"

if your fun_facts.txt is in the same file as the script, then you can just add the following line right after the SCRIPT_DIR definition:

readonly FUN_FACTS_TXT="$SCRIPT_DIR/fun_facts.txt"

hiulit

@meleu Thank you! Done! Works perfectly :D
Could you elaborate on how $(cd "$(dirname "$0") works? What does $0 mean? Thanks again!

hiulit

I found that if I specify a font when using convert it decreases the image creation time, like a lot!
It also depends on the sentence's length. But when specifying a font I get pretty good results with a 3 line sentence :O

real 0m3.338s
user 0m2.472s
sys  0m0.824s

compared to:

real 1m3.849s
user 0m12.148s
sys  0m1.024s

meleu

@hiulit said in shell scripting topic:

Could you elaborate on how $(cd "$(dirname "$0") works? What does $0 mean?

$0 is a positional parameter where the string you used to call the script is stored. More info about positional parameters can be found here (by the way, this doc has valuable info about bash scripting).

Now let me elaborate why I think that one-liner to get the script dir is a good way to go...

To ilustrate let's consider that the script was invoked from a different directory than the one where the script is placed. Let's consider the scenario I used as example on my post above, where I am calling the your script with this line:

prompt$  ./funfacts/es-fun-facts-splashscreens.sh

Now I'm going to break down this variable definition line (skipping the parts that I think you already know):

readonly SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"

$0 results in ./funfacts/es-fun-facts-splashscreens.sh
dirname "./funfacts/es-fun-facts-splashscreens.sh" results in./funfacts
cd "./funfacts" && pwd results in /FULL/PATH/TO/src/funfacts

I hope I was clear. :)

EDIT: if you want an extremely detailed and strong way to get the script's dir, take a look here: http://www.ostricher.com/2014/10/the-right-way-to-get-the-directory-of-a-bash-script/

It's a bit overkill for such a single task, but I would like to let the link here for future references. :)

hiulit

Hey, thanks again! It's crystal clear.

hiulit

For the fun facts splashscreens project I want to know which theme is currently active in EmulationStation and its font.

Here's what I'm doing:

function get_current_theme() {
    grep "name=\"ThemeSet\"" "$home/.emulationstation/es_settings.cfg" | sed -n -e "s/^.*value=['\"]\(.*\)['\"].*/\1/p"
}

function get_theme_font() {
    xmlstarlet sel -t -v "/theme/view[contains(@name,'detailed')]/textlist/fontPath" "$ES_DIR/themes/$current_theme/$current_theme.xml" 2> /dev/null
}

It's working but I don't know if it's the right way to do it.

Acutally, get_theme_font() is taken from @meleu 's generate-launching-imagesso I guess it should be ok :P

meleu

@hiulit I think they are just fine. Maybe get_current_theme() can be tweaked a little to be an one-liner sed. But as this is a small script, it's fine to keep it as is.

Another little thing I noticed is regarding that Regular Expression in the sed line. You don't need to explicitly match "start of the line followed by anything" (this is what ^.* means).

Also, I think we can tweak get_theme_font() in order to let it get the font for an arbitrary theme (defined by the user).