vsprintf

vsprintf

Write Formatted Output to a String

Portability: ISO/ANSI C conforming

SYNOPSIS
DESCRIPTION
RETURN VALUE
EXAMPLE
RELATED FUNCTIONS
SEE ALSO

SYNOPSIS

#include <stdarg.h>
#include <stdio.h>

int vsprintf(char *s, const char *format, va_list arg);

DESCRIPTION

vsprintf is equivalent to sprintf with arg replacing the variable-argument list. arg has been initialized by the va_start macro and possibly va_arg calls. vsprintf does not invoke the va_end macro. See va_arg, va_end, and va_start for details on varying-length argument-list functions.

RETURN VALUE

vsprintf returns the number of characters written in the array, not counting the terminating-null character.

EXAMPLE

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

static void format_msg(char *, int, int, ...);

#define NOTE 0
#define WARNING 1

main()
{
   char msgbuf[100];
   format_msg(msgbuf, NOTE, 0);
   printf("The formatted message is: "%s" \n", msgbuf);
   format_msg(msgbuf, WARNING,1, "a replacement string");
   printf("The formatted message is: "%s" \n", msgbuf);
   return;
}

static const char *msgs[]  = {
   "This is message number zero",
   "This message requires %s"
};

static const char *levels[]  = {
   "NOTE: ",
   "WARNING: "
};

static void format_msg(char *buf, int msgno, int level, ...)
{
   va_list args;
   va_start(args, level);

      /* Copy in the message prefix. Format the     */
      /*  remainder of the message with vsprintf(). */
   strcpy(buf, levels[level]);
   vsprintf(buf + strlen(levels[level]),msgs[msgno], args);
   va_end(args);
}

RELATED FUNCTIONS

sprintf , va_start , vformat , vsnprintf