vlfmt(3C)						   Standard C Library Functions 						 vlfmt(3C)

NAME

       vlfmt - display error message in standard format and pass to logging and monitoring services

SYNOPSIS

       #include <pfmt.h>
       #include <stdarg.h>

       int vlfmt(FILE *stream, long flag, const char *format, va_list ap);

DESCRIPTION

       The vlfmt() function is identical to lfmt(3C), except that it is called with an argument list as defined by <stdarg.h>.

       The  <stdarg.h>	header	defines  the type va_list and a set of macros for advancing through a list of arguments whose number and types may
       vary. The ap argument is of type va_list. This argument is used	with  the  <stdarg.h>  macros  va_start(),  va_arg(),  and  va_end().  See
       stdarg(3EXT). The example in the EXAMPLES section below demonstrates their use with vlfmt().

RETURN VALUES

       Upon  successful  completion,  vlfmt()  returns	the  number of bytes transmitted.  Otherwise, -1 is returned if there was a write error to
       stream, or -2 is returned if unable to log and/or display at console.

EXAMPLES

       Example 1 Use of vlfmt() to write an errlog()routine.

       The following example demonstrates how vlfmt() could be used to write an errlog() routine. The va_alist() macro is used	as  the  parameter
       list  in a function definition. The va_start(ap, ...) call, where ap is of type va_list, must be invoked before any attempt to traverse and
       access unnamed arguments. Calls to va_arg(ap, atype) traverse the argument list. Each execution of va_arg() expands to an  expression  with
       the  value and type of the next argument in the list ap, which is the same object initialized by va_start(). The atype argument is the type
       that the returned argument is expected to be. The va_end(ap) macro must be invoked when all desired arguments have been accessed. The argu-
       ment  list  in ap can be traversed again if va_start() is called again after va_end().) In the example below, va_arg() is executed first to
       retrieve the format string passed to errlog(). The remaining errlog() arguments (arg1, arg2, ...) are passed to vlfmt() in the argument ap.

	 #include <pfmt.h>
	 #include <stdarg.h>
	 /*
	  *   errlog should be called like
	  *	    errlog(log_info, format, arg1, ...);
	  */
	 void errlog(long log_info, ...)
	 {
		 va_list ap;
		 char *format;
		 va_start(ap, );
		 format = va_arg(ap, char *);
		 (void) vlfmt(stderr, log_info|MM_ERROR, format, ap);
		 va_end(ap);
		 (void) abort();
	 }

USAGE

       Since vlfmt() uses gettxt(3C), it is recommended that vlfmt() not be used.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       gettxt(3C), lfmt(3C), attributes(5), stdarg(3EXT)

SunOS 5.11							    29 Dec 1996 							 vlfmt(3C)