vswscanf() — Read Formatted Wide Character Data
Format
#include <stdarg.h>
#include <wchar.h>
int vswscanf(const wchar_t *buffer, const wchar_t *format, va_list arg_ptr);
Language Level
ANSI
Threadsafe
Yes
Locale Sensitive
The behavior of this function might be affected by the LC_CTYPE and LC_NUMERIC categories of the current locale. It might also be affected by the LC_UNI_CTYPE and LC_UNI_NUMERIC categories of the current locale if LOCALETYPE(*LOCALEUCS2) or LOCALETYPE(*LOCALEUTF) is specified on the compilation command. This function is not available when LOCALETYPE(*CLD) is specified on the compilation command. For more information, see Understanding CCSIDs and Locales.
Wide Character Function
See Wide Characters for more information.
Description
The vswscanf()
function
reads wide data from a buffer into locations specified by a variable
number of arguments. The vswscanf()
function works
just like the swscanf()
function,
except that arg_ptr points to a list of
arguments whose number can vary from call to call in the program.
These arguments should be initialized by va_start for
each call. In contrast, the swscanf()
function can
have a list of arguments, but the number of arguments in that list
is fixed when you compile the program.
Each argument must be a pointer to a variable with a type
that corresponds to a type specifier in format-string. The format has
the same form and function as the format string for the swscanf()
function.
Return Value
The vswscanf()
function
returns the number of fields that were successfully converted and
assigned. The return value does not include fields that were read
but not assigned. The return value is EOF for an attempt to read at
end-of-file if no conversion was performed. A return value of 0 means
that no fields were assigned.
Example
vswscanf()
function
to read various data from the string tokenstring and then displays
that data. #include <stdio.h>
#include <stdarg.h>
#include <wchar.h>
int vread(const wchar_t *buffer, wchar_t *fmt, ...)
{
int rc;
va_list arg_ptr;
va_start(arg_ptr, fmt);
rc = vswscanf(buffer, fmt, arg_ptr);
va_end(arg_ptr);
return(rc);
}
int main(void)
{
wchar_t *tokenstring = L"15 12 14";
char s[81];
char c;
int i;
float fp;
/* Input various data */
vread(tokenstring, L"%s %c%d%f", s, &c, &i, &fp);
/* Display the data */
printf("\nstring = %s\n",s);
printf("character = %c\n",c);
printf("integer = %d\n",i);
printf("floating-point number = %f\n",fp);
}
/***************** Output should be similar to: *****************
string = 15
character = 1
integer = 2
floating-point number = 14.000000
*******************************************************************/