[comp.unix.xenix.misc] problem with varargs.h in Xenix 2.3.3

statham@cactus.org (Perry L. Statham) (04/25/91)

/*
Can anyone tell me why this program does not compile and how to fix it.

Operating System:
    SCO Xenix 2.3.3
    Dev Kit Release 2.3.0d
        
Compiler Message:
    testprog.c(19) : error 65: 'va_alist' : undefined

Line 19 is the line that has va_start on it.

The release lines for the two header files are:
    *	@(#) stdio.h 1.10 88/10/26 
    *	@(#) varargs.h 1.1 88/10/26 

Any help is appreciated.

Perry Statham
perry@statham.cactus.org
(512) 335-3881 (Home)
(512) 467-1396 (Work)

*/

#include <stdio.h>
#include <varargs.h>

void sceprintf( char *, 
                ... );  

main() {
  sceprintf("0x%x %d\n",1,1);
}

void sceprintf( format, ... )
char *format;
{
  FILE *log;
  va_list argptr;

  if ((log = fopen("logfile","a+")) != NULL) {
    va_start(argptr);
    vfprintf(log,format,argptr);
    va_end(argptr);
    fclose(log);
  }
} 

aryeh@eddie.mit.edu (Aryeh M. Weiss) (04/25/91)

In article <6596@cactus.org> statham@cactus.org (Perry L. Statham) writes:
>
>/*
>Can anyone tell me why this program does not compile and how to fix it.
>        
>Compiler Message:
>    testprog.c(19) : error 65: 'va_alist' : undefined
>
...
>void sceprintf( format, ... )
>char *format;
>{
>  FILE *log;
>  va_list argptr;
>
>  if ((log = fopen("logfile","a+")) != NULL) {
>    va_start(argptr);
>    vfprintf(log,format,argptr);
>    va_end(argptr);
>    fclose(log);
>  }
>} 

There are two implementations of ``varargs'' in Xenix.
The header <varargs.h> is for K&R coding styles while <stdarg.h>
is for ANSI coding style.  The va_start is defined differently in
the two styles.  Since you are using an almost ANSI
coding style you could try the following:

#include <stdarg.h>
void sceprintf(char *format, ... )
{
  FILE *log;
  va_list argptr;

  if ((log = fopen("logfile","a+")) != NULL) {
    va_start(argptr,format);		/* Makes argptr point to 1st argument
					AFTER format */
    vfprintf(log,format,argptr);
    va_end(argptr);
    fclose(log);
  }
} 


For K&R coding style use:

#include <varargs.h>
void sceprintf(format, va_alist)
char *format; va_dcl			/* NO semicolon! */
{
  FILE *log;
  va_list argptr;

  if ((log = fopen("logfile","a+")) != NULL) {
    va_start(argptr);		/* Makes argptr point to va_alist */
    vfprintf(log,format,argptr);
    va_end(argptr);
    fclose(log);
  }
}