How to best cope with variadic input

richardcavell@mail.com richardcavell@mail.com
Tue Mar 1 05:12:00 GMT 2011


Hi everyone.  I've decided to learn C99, and so I'm passing -std=c99 to 
gcc.  I've decided to write a Wikipedia bot in C (don't laugh).

Owing partly to obsessive tendencies and partly due to the need for the 
bot to be robust in working unattended at high speed, I want to wrap 
printf in a wrapper that automatically detects when printf has failed 
and tells the user.  The idea is that it is called like this:

int res = safeprint ( __FILE__ , __LINE__ , "Blah" ) ;
if ( res < 0 ) // uh oh

  But printf has variadic input.  I am scratching my head wondering what 
is my best option:

1.  Make safeprint a variadic function  (I don't know how to do this)
2.  Turn on C++ and overload safeprint with different combinations of 
arguments
3.  Create multiple safeprint functions with different names, that take 
different combinations of arguments

Any advice for me?  TIA.

-----------------------------------
#include <stdio.h>
#include <string.h>

#include "Error.h"

static const unsigned int StringMax = 100 ;

int safeprint ( const char* file , const unsigned int line , const 
char* pstring )
{
    int ilength = strlen ( pstring ) ;
    int icharsprinted = printf ( "%s" , pstring ) ;
    if ( ilength != icharsprinted )
    {
        Error ( file , line ) ;
        return -1 ;
    }

    return 0 ;
}




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