Header File 

io.h  

Category 

Memory and String Manipulation Routines 

Prototype 

int vsscanf(const char *buffer, const char *format, va_list arglist); 

Description 

Scans and formats input from a stream. 

The v...scanf functions are known as alternate entry points for the ...scanf functions. They behave exactly like their ...scanf counterparts, but they accept a pointer to a list of arguments instead of an argument list.

vsscanf might stop scanning a particular field before it reaches the normal end-of-field (whitespace) character, or it might terminate entirely, for a number of reasons. See scanf for a discussion of possible causes. 

Return Value 

vsscanf returns the number of input fields successfully scanned, converted, and stored; the return value does not include scanned fields that were not stored. If no fields were stored, the return value is 0. 

If vsscanf attempts to read at end-of-string, the return value is EOF. 

Example  

#include <stdio.h>
#include <stdarg.h>
char buffer[80] = "30 90.0 abc";
int vssf(char *fmt, ...)
{
   va_list  argptr;
   int cnt;
   fflush(stdin);
   va_start(argptr, fmt);
   cnt = vsscanf(buffer, fmt, argptr);
   va_end(argptr);
   return(cnt);
}
int main(void)
{
   int inumber;
   float fnumber;
   char string[80];
   vssf("%d %f %s", &inumber, &fnumber, string);
   printf("%d %f %s\n", inumber, fnumber, string);
   return 0;
}

Portability