cascading stdarg calls

[cornelis van der bent]

Hi, the code below prints a garbage "world" value to <messages>;
"Hello " is fine. What can be the problem?

static char messages[LARGE_ENOUGH];

int writeText(char* text, char* format, ...)
{
va_list argumentList;

va_start(argumentList, format);
vsprintf(text, format, argumentList);
va_end(argumentList);
}

void writeMessage(char* format, ...)
{
va_list argumentList;

va_start(argumentList, format);
writeText(protocolText, format, argumentList);
va_end(argumentList);
}

void test(void)
{
writeMessage("Hello %s!\n", "world");
}

Thanks,

Cornelis

 

[cornelis van der bent]

The problem is that you cannot call a function with "..." passing
it a va_list. You have to create a function accepting a va_list
as argument.

Thanks for the quick answer! It's already in my code now and of
course works.

Cornelis

 

[cornelis van der bent]

This is a FAQ:http://c-faq.com/varargs/handoff.html

You have to read the linked FAQs first.

Thanks for pointing this out. Apologies! I did search google for a
short period but without succes, but had forgotten to look in the good
old C-FAQ.

Cornelis

 

[Seebs]

Hi, the code below prints a garbage "world" value to <messages>;
"Hello " is fine. What can be the problem?

A va_list is not the same as a series of arguments. You need to use
a va_list argument to writeText, not a ...

-s