Managing variable argument call

[sphinx.moro]

Hello,
I have a function which is coded to receive an unknown number of
arguments
void Process(int i_ss, int Nerr, ...) {
va_list pa; /* variable argument list*/
va_start(pa, Nerr);
sprintf(FMT, "SS=%d, Er=%d ", i_ss, Nerr);
strcat(FMT, "A1=<%s>, A2=<%s> ");
vsprintf(line, FMT, pa);
va_end(pa);
printf("%s\n", line);
fflush(stdout);
}
Here, for simplicity, I treat2 args ,
I want to call this function from a input scenario that will give
textually the type, and value of arguments
I will decode this scenario to call the function
For example a line of scenario could be:
S=P1 S=P2
The I will cal with 2 strings
S=P1 S=P2 I=13
The I will cal with 2 strings and one int
Obviouly I need to have a format which is suitable for that.
--
I have made some experience with "alloca"
for allocation space in the stack, "pushing" arguments on the stack
and calling the function.
snippet: ARGS has been set previously
-------------------------------------------------------------------------------------
parguments = (void*) alloca(size); /* 8 in the case depicted
(2 char pointers) */
for (p=0; p < nargs;p++){
/* Get the code for the argument
*/
switch(ARGS[p].code){
case 'S' :
*(((char**)parguments)++) = ARGS[p].str; //P1
break;
case 'I' :
/* value
*/
*(((int*)parguments)++) = ARGS[p].vali; //P2
break;
default:
;
}
}
Process(i_ss, NumError);

 

[Chris Torek]

I have a function which is coded to receive an unknown number of
arguments

(You mean "variable number of arguments", in Standard-ese anyway.)

... I want to call this function from [some other function

that needs to supply the variable number of arguments By Magic.]

This is in the FAQ. See the comp.lang.c FAQ, question 15.13
(<http://c-faq.com/varargs/invvarargs.html>).