Lua Programming Help Thread

[TheBressman]

What's the command to make a new file and the command to paste ?
TP's idea sounded right to me, but it didn't work (see post above Shroom's)

[Anti-QuickJay]

He just copies the stuff inside a file and paste it inside another file, It doenst make a new file.
His is like copy and overwrite.

[TheBressman]

I think it actually creates the file if it doesn't exist.
Anyway, what is that error !? What does it mean ?

[TacticalPenguin]

No, you can make a new file, itll automatically create the file you write to if it isnt there. And thats basically the only way to do it. And by .ext i mean .extension, whatever the extension is.

[Anti-QuickJay]

Ah, I didn't know that it would automatically make the file, Well im always learning.

[TheBressman]

Lol yeah I know that ext is the extension of the file. I need to know how to fix the error lol ! :)

EDIT: I seem to have fixed that error, a file now appears in the directory I've indicated, however, it is only 1KB in size and contains only 2F6E 0C20 0B20 0220 2F6E (/n . . . /n). I'm not so sure what's wrong...

function backup( )
System.currentDirectory(" c:/scripts")
copy = io.open("something.dat"," r")
for line in copy:lines( ) do
System.currentDirectory(" c:/")
paste = io.open("something.dat"," w")
paste:write(line.."/n")
end
end

[SG57]

I found an interesting set of functions, it allows you to load and save tables to and from files:

http://lua-users.org/wiki/SaveTableToFile

If what your planning on in the end is to save and load tables, as if you were loading a saved game (like level, map, guns, ammo, etc.), than use this.

If not, than your problem there is, im guessing, is 'lines' is simply the hex offset of what line your on... Also, if your tring to copy exactly the same as the file you loaded in, there is no need for hte '\n', as file:read also reads in the newline character, so youd actually be double spacing whatever file your triyng to copy ;)

function backup( )
System.currentDirectory(" c:/scripts")
copy = io.open("something.dat"," r")
paste = io.open("something.dat"," w")
System.currentDirectory(" c:/")
for line in copy:lines( ) do
paste:write(line)
end
end

Try that...

If it doesnt work, ill take the time to write a working one (im searching ebay for some stuff, but i can take a break ;))

[BlackShark]

hey TP,

Im trying to make it so that in a browser, if you click on a directory that contains "index.lua" then it runs that file., Would you, (or any body else) know how to do that?

[TheBressman]

@SG57: Cheers, but now I get the same error as before
(error: Attempt to index global 'copy' (a nil value))

EDIT: Lol, this is getting crazy. I fixed it again by getting rid of some stupid spaces I put in, but the file created consists of 4C4F 434B FFFF 32 (LOCK..2).

[SG57]

BlackShark - look at gpack v.2, as TP made that one. But honestly, its not all that hard... This is basically what you are asking for:

fileSystem = System.listDirectory("ms0:/")
file = 1
oldpad = Controls.read()

while true do
  pad = Controls.read()
  if pad ~= oldpad then
    if pad:up() and file > 1 then file = file - 1
    elseif pad:down() and file < table.getn(fileSystem) then file = file + 1 end

    if pad:cross() and fileSystem[file].name == "index.lua" then dofile(fileSystem[i].name) end
  end

  screen:clear()
  for i=1,table.getn(fileSystem) do
      screen:print(10,i*10,fileSystem[i].name,Color.new(255,255,255)) 
  end
  screen:print(11,file*10,fileSystem[file].name,Color.new(0,255,0))

  screen.waitVblankStart()
  screen.flip()
  oldpad = pad
end

Very simpleand easy to make, dont be fooled now.
-= Double Post =-
TheBressman - post exactly what you have, as Id like to work with your exact code so I know its not YOU making hte mistake during hte copy&paste.

[TheBressman]

Alright then.

-- Registry backup function
function backup( )
System.currentDirectory(" c:/registry")
copy = io.open("system.dreg","r" )
System.currentDirectory(" c:/")
paste = io.open("system.dreg","w" )
for line in copy:lines( ) do
paste:write(line)
end
end

PS: Weird forum editing is putting a space between " and c in "c:/registry" and "c:/"

[myschoo]

Try something like:

memfree = System.getFreeMemory()/1024/1024
print("About "..math.floor(memfree+0.5 ).." megabytes of free memory")

The math.floor(memfree+0.5) part rounds it to the nearest number. It's about, not exactly.

the strange thing is, that System.getFreeMemory / 1024 / 1024 will get number 18, but my free memory is 288..... strange o_O

[SG57]

TheBressman - Try this:

System.currentDirectory ("c:/registry/")

Instead of what you have.

[myschoo]

PLS can anyone test:

System.getFreeMemory()

in his PSP ????????

does this get free memory on memory stick???

[SG57]

myschoo - System.getFreeMemory returns the number of bytes free on the memory card. To get kilobytes, divide it by 1000. To get megabytes, divide it by 1000000. So...

screen:print(0,0,System.getFreeMemory/1000000 .. "megabytes",Color.new(255,0,0))

Does this or does this not print out how much space you have free, if not, than your memory stick must have some weird formatting or be fake or something...

[EminentJonFrost]

it gives you the free space of ram, not the memory stick. lol

edit - i double posted...lol

[myschoo]

omg
i thought so... Lol !
because i have SanDisk Ultra II 100% percent not fake...

thx for explanation Eminent ;)

[SG57]

Hmm... to get free space from memory, maybe... First get how much memory has been used on the memory stick by adding up all the sizes of the files found through a recursive scan of 'ms0:/' and add that to the amount able to be written. So - write to a file, one byte at a time, or 100 bytes at a time, or some interval for how accurate you want to be, until it cant write anymore. Thats my theory...

[HeaD_ShOt]

how to unload images from ram?

[SG57]

headshot - To free anything from RAM, set it's value to nil.

image = Image.load("blah.png") -- allocate memory for image and store image data
image = nil -- free image data from ram

sound = Sound.load("blah.wav") -- allocate memory for sound and store it
sound = nil -- free sound data from memory

[yaustar]

headshot - To free anything from RAM, set it's value to nil.

image = Image.load("blah.png") -- allocate memory for image and store image data
image = nil -- free image data from ram

sound = Sound.load("blah.wav") -- allocate memory for sound and store it
sound = nil -- free sound data from memory

Slightly incorrect. You have to 'nil' or remove all references to the data in RAM.

Blah = Image.load("blah.png"); -- allocate memory for image and store image data
Blah2 = Blah;
Blah = nil; -- blah.png not flagged for removal for the garbarge collection because Blah2 still references to it
Blah2 = nil -- blah.png is now flagged for removel for the garbarge collection because no variables reference to it

[EminentJonFrost]

Slightly incorrect. You have to 'nil' or remove all references to the data in RAM.

Blah = Image.load("blah.png"); -- allocate memory for image and store image data
Blah2 = Blah;
Blah = nil; -- blah.png not flagged for removal for the garbarge collection because Blah2 still references to it
Blah2 = nil -- blah.png is now flagged for removel for the garbarge collection because no variables reference to it

but what if Blah2 wasnt there in the first place? THEN would SG be "fully" correct?

[yaustar]

but what if Blah2 wasnt there in the first place? THEN would SG be "fully" correct?

No, he will be partially correct.

[pspfreak9]

When i start this it just shows the black screen from when the loop starts. But how come the if statment doesnt worK!!??

white =Color.new(255,255,255)
red =Color.new(255,0,0)
background =Image.load("Background.png")
man =Image.load("Man.png")
x,y = 240,136;

screen:clear()
screen:print(0,0,"Connecting...",Color.new(255,0,0))
screen.flip()
dofile("netlib.lua")
netlib_server = "66.25.53.65"
Wlan.init()
Wlan.useConnectionConfig(1)
System.sleep(50)
screen.flip()
screen:print(0,10,"Connecting to netlib...",Color.new(255,255,255))
screen.flip()
netconnect()
System.sleep(50)
screen.flip()
y = 0
p1 = y
netsend("p1",y,"w")
netget("p1")


while true do
screen:clear()
	netrecv()
	buffer = netvalue("p1")
		if buffer == "0" then 
			screen:print(0,0,buffer,red)
           end
screen.waitVblankStart(); 
screen.flip()
end

-= Double Post =-
That is just pat of my game by the way
-= Double Post =-
Anyone??

[EminentJonFrost]

maybe cause 'buffer' does not equal zero...lol
from what you posted, it looks like theres something going in netlib.lua affecting 'buffer'.
(but i cant tell since buffer doesnt even show up anywhere in the script you put up before that 'if' loop)

[pspfreak9]

Buffer is netvalue("p1") and i sent 0 to p1 read from the begining

[EminentJonFrost]

if by some slim chance, your problem wasnt from net coding, i mightve been able to help. but i'm no use here since it is.
sorry.

[pspfreak9]

ok thx for trying anyone have experinece coding with netlib

[SG57]

pspfreak - Your comparing "0" to buffer. Your saying you sent the value 0, not the char '0', so it shouldnt run as 0x00 is differnent than 0x30.

[BlackShark]

Aright, im Editing TP's browser, and want to make it so that if you click on a directory with "index.lua" inside it then it launches the index.lua.

This is what I have so far?

if pad:cross() and oldpad:cross() ~= pad:cross() and bfold == true and fl[s].directory == true then
System.currentDirectory(f l[s].name)
s = 1
fl=System.listDirectory()
nf=table.getn(fl)
elseif pad:cross() and oldpad:cross() ~= pad:cross() and bfold == true and fl[s].directory == true and string.lower(fl[s].name) == "index.lua" then
dofile("index.lua")
System.currentDirectory(" ./../..")
end