Getting the rom name and emulator

daveyman123

very informative Cyperghost. Thank You. so basically retropie is written in bash or am i way off?

BuZz

@daveyman123 RetroPie-Setup (the installer script etc) is written in bash and so is the launch script. Components are written in various other languages (C/C++/Python).

BuZz

@cyperghost I don't understand your question.

cyperghost

@buzz I call a python programm with $@ within runcommand. What will be the result and how does the python script "knows" how many arguments are given.

So if
$1 - the system (eg: atari2600, nes, snes, megadrive, fba, etc).
$2 - the emulator (eg: lr-stella, lr-fceumm, lr-picodrive, pifba, etc).
$3 - the full path to the rom file.
$4 - the full command line used to launch the emulator

can I just use romfile=$3 variable within python and I get my romfile even by using $@?

BuZz

@cyperghost "$@" is all the parameters. eg it expands to

"$1" "$2" "$3" (for any parameters that exist) so it will pass all the parameters on to the python script

https://stackoverflow.com/questions/4824590/propagate-all-arguments-in-a-bash-shell-script#4824637

daveyman123

@BuZz
@cyperghost
either of you know why i would have to powercycle my entire raspberry pi to get the "Pimoroni Unicorn Hat" to work more than once i.e. it screws up and lighting is random after one scroll through?

BuZz

@daveyman123 no idea.

meleu

@cyperghost said in Getting the rom name and emulator:

@buzz I call a python programm with $@ within runcommand. What will be the result and how does the python script "knows" how many arguments are given.

So if
$1 - the system (eg: atari2600, nes, snes, megadrive, fba, etc).
$2 - the emulator (eg: lr-stella, lr-fceumm, lr-picodrive, pifba, etc).
$3 - the full path to the rom file.
$4 - the full command line used to launch the emulator

can I just use romfile=$3 variable within python and I get my romfile even by using $@?

I'm not comfortable with python at all, I only learned it to tweak the joy2key tool and never used it again. But I think the answer for your question can be found here: https://docs.python.org/2/library/sys.html#sys.argv

Maybe this example can answer too:

[PROMPT] $ cat args.py 
#!/usr/bin/python

import sys

print '\nnumber of arguments:'
print len(sys.argv)

print '\nhere are the given arguments:'
for arg in sys.argv:
    print arg

print '\nhere is the third argument:'
print sys.argv[3]


[PROMPT] $ ./args.py one two three

number of arguments:
4

here is the given arguments:
./args.py
one
two
three

here is the third argument:
three

[PROMPT] $ ./args.py catch errors

number of arguments:
3

here is the given arguments:
./args.py
catch
errors

here is the third argument:
Traceback (most recent call last):
  File "./args.py", line 13, in <module>
    print sys.argv[3]
IndexError: list index out of range

cyperghost

@meleu That's it
Thank you

daveyman123

@cyperghost

Would you know why something about launching a game stops my unicorn hat from functioning?

If I launch a game and immediately back out it will continue to scroll through the rom on the unicorn hat.

However,
if the game actually launches the unicorn hat stops.
would there be something interfering with the PINS from retropie?

I have the python script running in the background but no difference.

cyperghost

@daveyman123 That isn't hard

nano /opt/retropie/configs/all/runcommand-onstart.sh
Add your script for ex /home/pi/RetroPie/loop.sh $1 &

That's it

code example loop.sh
make loop executable by chmod +x loop.sh

#!/bin/bash 
counter=0
while [  $counter -lt 10 ]; do
echo The counter is $counter
echo "The romsystem is $1" >> /tmp/counter.log
let counter=counter+1 
sleep 5
done

That's it ... now in tmp/counter.log is 10 times written "The romsystem is ....."
As the ROM is loaded in foreground the bash example in background is logging the system.

daveyman123

@cyperghost
almost done writing it up
if this works youre a genius!

meleu

@daveyman123 can you tell me WTF is an unicorn hat?
I want to believe that you are not talking about this:
unicornhat

@cyperghost I remember that you said you didn't learn programming in a "formal" way. But I would like to make you care more about the importance of indentation.

Please, I don't want to sound like the smart guy teaching you the right way to code. If your code works for you, then it's fine. But I know that you like to share code with the community (giving and receiving contributions), and for this purpose indentation is a basic requirement. ;-)

Sano

More like this I think : https://shop.pimoroni.com/products/unicorn-hat
But yours is way more fun :D

meleu

@sano said in Getting the rom name and emulator:

But yours is way more fun

haha! both models are kinda psychodelic! :D

daveyman123

@cyperghost
here is the python script. I think its reading the log just fine.

from UHScroll import *
import sys
import time
import os
import unicornhat as unicorn
infile = r"/tmp/counter.log"

#print len(sys.argv)
#emulator_name = $1
#emulator_name = os.environ["$1"]
#emulator_name = os.path.basename(os.path.normpath(sys.argv[3]))
with open(infile) as f:
    f = f.readlines()

for line in f:
        rom_name = line
        unicorn_scroll(rom_name,'white',255,0.2)`

daveyman123

and here is the loop bash script

#!/bin/bash
counter=0
while [ $counter -lt 10 ]; do
echo The counter is $counter
echo "$3" >> /tmp/counter.log
let counter=counter+1
sleep 5
sudo python /opt/retropie/configs/all/onstart2.py
sleep 5
done

and here is the startup script (runcommand-onstart.sh)

/home/pi/RetroPie/loop.sh $1 &
sudo python onstart2.py "$1" &

cyperghost

@meleu A Unicorn Hat seem to be a LED grid of 8x8. So it can be used/abused as simple display. As far as I understood this

Yes the code is of course messy and unclean ... it's just an example that a bash file can run in the background by wrinting a logging file. I don't have an code editor so everything is written in nano. I'm thankfull for every tip and I appreciate your way you tell me do and what is better not done!

@daveyman123 Thanks for your comment but please don't call me genius for writing a simple bash script. There are others that do programming as profession. I do it just for hobby and still make lot of errors ... like missing indentation or not using remarks for this.