How do you assign a string ?

Comments

• CJ Posts: 470

  2007-03-27 12:28 edited 2007-03-27 12:28

  use a bytemove(@tempstr, @string, strsize(@string))
  
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  Post Edited (CJ) : 3/27/2007 12:33:42 PM GMT
• Bean Posts: 8,129

  2007-03-27 13:02 edited 2007-03-27 13:02

  Thanks, that makes alot more sense.
  
  Bean.
  
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• Kaio Posts: 253

  2007-03-27 13:34 edited 2007-03-27 13:34

  A good way for this is to locate your strings in the DAT section.
  

  VAR
    BYTE tempStr[noparse][[/noparse]255]
  
  PUB fillStr | size
  
    size := strsize(@myText) 
    bytemove(@tempstr, @myText, size)
    tempStr[noparse][[/noparse]size] := 0
    
  
  DAT
  myText                  byte    "My Text",0
  
  
• CJ Posts: 470

  2007-03-27 16:11 edited 2007-03-27 16:11

  I forgot to move the 0 terminator, so it would be
  
  bytemove(@tempstr, @string, strsize(@string) + 1)
  
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• Chicago Mike Posts: 88

  2007-06-06 23:33 edited 2007-06-06 23:33

  Relating to this: Is it possible to reference a single character in the string array and move it to a new variable as well using this method? Just use a String size of 1? I've been having an issue extracting a single character from an input serial string. Just curious
  
  temp:= strarray ' doesn't work to get the 4th character.
• Paul Baker Posts: 6,351

  2007-06-06 23:47 edited 2007-06-06 23:47

  In that case you can use the BYTE operator:
  
  

  temp := BYTE[noparse][[/noparse]@strarray][noparse][[/noparse]x]
  

  
  where x is the zero based character position you want to copy (x=0 is the first character)
  
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  Propeller Applications Engineer
  
  Parallax, Inc.
• Chicago Mike Posts: 88

  2007-06-07 12:00 edited 2007-06-07 12:00

  HUmmm Thats what I've been trying with no luck. Below is the code I'm running. I've declared in the VAR section: byte buf[noparse][[/noparse]127]
  I"m using this with a serial receiver, and the string its receiving right now as a test is 'BOB'. The string is being received, and I can display the entire string, but the plucking of a single character is the issue I'm having
  
  PUB radiorx | temp
  repeat
  ifnot ina[noparse][[/noparse]Busy]
  ina[noparse][[/noparse]Ready]:=Low
  buf:=serial.rx
  ina[noparse][[/noparse]Ready]:=High
  temp:=BYTE[noparse][[/noparse]@buf]
  tv.str(@buf) '' Displays the entire string without a problem
  tv.str(temp) " Displays nothing
  else
  waitcnt(500_000+cnt)
  
  I've got to be missing something stupid
• CardboardGuru Posts: 443

  2007-06-07 15:07 edited 2007-06-07 15:07

  Hi Mike,
  
  In the first case you're passing a pointer to a string terminated by zero.
  In the second case you're passing a long with the actual character in the low 8 bits.
  If you passed tv.str(@temp) I would think it would (accidentally) work, because the long is stored in little endian format, and the upper 24 bits are zero, which will provide the zero termination on the string.
  
  i.e.
  if the string is BOB,
  temp:=BYTE[noparse][[/noparse]@buf] will cause temp to be equal to $00000042. And this is stored in memory the same way as BYTE $42,$00,$00,$00.
• Paul Baker Posts: 6,351

  2007-06-07 15:51 edited 2007-06-07 15:51

  He is correct, tv.str expects a pointer to a string. A string is a series of characters followed by a 0, so the following code would work
  
  

  temp.byte[noparse][[/noparse]0] := BYTE[noparse][[/noparse]@buf]
  temp.byte[noparse][[/noparse]1] := 0
  tv.string(@temp) 
  

  
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  Paul Baker
  Propeller Applications Engineer
  
  Parallax, Inc.
• Chicago Mike Posts: 88

  2007-06-07 23:12 edited 2007-06-07 23:12

  I see the error of my ways, and that makes sense. I tried it and I do get a copy, zero terminated into temp and can display it. My issue is that I can't figure out how to pluck a single character. Say I want to only copy the 3rd character of the string in buf into the temp.byte[noparse][[/noparse]0]. Thats were I'm having difficulties. Since I'm referencing buf at the address, do I have to somehow offset the address of buf?
  
  So from BOB as the string, I want to only grab the second B and save it in temp.
  
  Thanks!
• CardboardGuru Posts: 443

  2007-06-07 23:16 edited 2007-06-07 23:16

  This should do it.
  
  

  temp.byte[noparse][[/noparse] 0] := BYTE[noparse][[/noparse]@buf][noparse][[/noparse] 2]
  temp.byte[noparse][[/noparse] 1] := 0
  tv.string(@temp)
  

  
  Post Edited (CardboardGuru) : 6/7/2007 11:21:07 PM GMT
• Chicago Mike Posts: 88

  2007-06-07 23:30 edited 2007-06-07 23:30

  I gave that a shot as I thought that syntax would work as well, however I don't get anything.
  
  temp.byte[noparse][[/noparse] 0] := BYTE[noparse][[/noparse]@buf]
  temp.byte[noparse][[/noparse] 1] := 0
  tv.string(@temp)
  
  So the above proves that the variable is copying to temp, as that the tv.string displays BOB . However when I add the reference to any array record of buf (Single character), I get nothing. (Below like you said). IS there some problem with referencing an index off of a referenced address like this?
  
  temp.byte[noparse][[/noparse] 0] := BYTE[noparse][[/noparse]@buf][noparse][[/noparse] 2]
  temp.byte[noparse][[/noparse] 1] := 0
  tv.string(@temp)
  
  Very odd.
• Paul Baker Posts: 6,351

  2007-06-07 23:31 edited 2007-06-07 23:31

  Chicago Mike said...
  I gave that a shot as I thought that syntax would work as well, however I don't get anything.
  
  temp.byte[noparse][[/noparse] 0] := BYTE[noparse][[/noparse]@buf]
  temp.byte[noparse][[/noparse] 1] := 0
  tv.string(@temp)
  
  So the above proves that the variable is copying to temp, as that the tv.string displays BOB

  This code should not display BOB, it should display B
  
  Take a look at page 167 and 168 of the manual, double indexing is a valid syntax and it works.
  
  Get back to basics, instead of trying to cast the character into a string use tv.out (or tv.print depending on which driver you are using) so do tv.out(BYTE[noparse][[/noparse]@buf][noparse][[/noparse] 2])
  
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  Paul Baker
  Propeller Applications Engineer
  
  Parallax, Inc.
  
  Post Edited (Paul Baker (Parallax)) : 6/7/2007 11:39:32 PM GMT