[C400-L] Returning character variables from C to RPG

[Krish Thirumalai <krishnithya@xxxxxxxxx>]

Writing my first program in C in the ILE environment and I am really 
puzzled.

I have the following RPG program that is calling a C function, but all i get 
back is a Null each time. If i put it in debug mode i can see that the value 
of chkdigit is correct, but then, when i get it back in my RPG, the value is 
NULL.

Can someone point out what i am doing wrong ?

RPG program

D Pr_ChkDigit PR * ExtProc('Pr_ChkDigit') 
D * Options(*string) value 

D Wrk_Str s 36A 
D Wrk_Null s 1A Inz(X'00') 
D Wrk_ChkDigit s 1A 
D Ptr_ChkDigit s * INZ(%ADDR(Wrk_ChkDigit)) 

/Free 
Wrk_Str = '70500607050AEI02x' + Wrk_Null; 
Ptr_ChkDigit = Pr_ChkDigit(%Addr(Wrk_Str)); 
Dsply Wrk_ChkDigit; 
*InLr = *on; 
/End-Free 

C service program

// Mod 36 Check bit calculator 
char* Pr_ChkDigit(char *str) 
{ 

char chkdigit; 
char* check_bit; 

//Calcuations 
// Get checkbit from the Mapping Matrix 
chkdigit=reverse_map(c1,c2) ; 
*check_bit = chkdigit; 
return check_bit; 

} 



-- 
Krish Thirumalai