bytefill and bytemove

nicolad76

Hi,
readingfrom Prop Manual:
[...]
Using BYTEFILL
BYTEFILL is a great way to clear large blocks of byte-sized memory. For example:

VAR
byte Buff[100]
PUB Main
bytefill(@Buff, 0, 100) 'Clear Buff to 0
[...]

and

[...]
BYTEMOVE is a great way to copy large blocks of byte-sized memory. For example:
VAR
byte Buff1[100]
byte Buff2[100]
PUB Main
bytemove(@Buff2, @Buff1, 100) 'Copy Buff1 to Buff2
[...]

So, in order to extract a substring I wrote the following code:

var


 byte command[56]
 byte cmd[4]
 byte params[51]
  
PUB Main 

 pst.Start(115_200) 

 repeat
       pst.StrIn(command)      
       pst.Str(String(pst#NL, pst#NL, "COMMAND 1: "))
       pst.Str(command)

       bytemove(@cmd,@command,3) ' copy 3 bytes from command to cmd   
       bytefill(@cmd+3,0,1)      ' add zero-termination string

       pst.Str(String(pst#NL, pst#NL, "COMMAND 2: "))
       pst.Str(command)

       pst.Str(String(pst#NL, pst#NL, "CMD: "))
       pst.Str(cmd)

output is

COMMAND 1: 1234567890

COMMAND 2: 1234567890

CMD: 1234567890

if i try (bcs I was desperate and I tried all permutations....)

       bytemove(cmd,command,3) ' copy 3 bytes from command to cmd   
       bytefill(cmd+3,0,1)      ' add zero-termination string

the output will be:
COMMAND 1: 1234567890

COMMAND 2: 123

CMD: 123

which looks fine but the original value of the variable "command" seems to be corrupted.

Why all this happens?
Thanks
Nicola

kuroneko

You need to pass the address of your byte arrays. Try this:

var
 byte command[56]
 byte cmd[4]
 byte params[51]
  
PUB Main 

 pst.Start(115_200) 

 repeat
       pst.StrIn([COLOR="Red"]@[/COLOR]command)      
       pst.Str(String(pst#NL, pst#NL, "COMMAND 1: "))
       pst.Str([COLOR="Red"]@[/COLOR]command)

       bytemove(@cmd,@command,3) ' copy 3 bytes from command to cmd   
       [COLOR="Blue"]cmd[3] := 0[/COLOR]               ' add zero-termination string [COLOR="Blue"](simpler)[/COLOR]

       pst.Str(String(pst#NL, pst#NL, "COMMAND 2: "))
       pst.Str([COLOR="Red"]@[/COLOR]command)

       pst.Str(String(pst#NL, pst#NL, "CMD: "))
       pst.Str([COLOR="Red"]@[/COLOR]cmd)

nicolad76

All right!!!! I was looking for the problem in the wrong place!!!
thanks, it worked!!!!
Nicola