Note
Access to this page requires authorization. You can try signing in or changing directories.
Access to this page requires authorization. You can try changing directories.
Write formatted output using a pointer to a list of arguments.
int_vsnprintf(char*buffer,size_tcount**,constchar*format,va_listargptr);**
int_vsnwprintf(wchar_t*buffer,size_tcount**,constwchar_t*format,va_listargptr);**
| Routine | Required Header | Optional Headers | Compatibility |
| _vsnprintf | <stdio.h> and <stdarg.h> | <varargs.h>1 | Win 95, Win NT |
| _vsnwprintf | <stdio.h> or <wchar.h>, and <stdarg.h> | <varargs.h>1 | Win 95, Win NT |
1 Required for UNIX V compatibility.
For additional compatibility information, see Compatibility in the Introduction.
Libraries
| LIBC.LIB | Single thread static library, retail version |
| LIBCMT.LIB | Multithread static library, retail version |
| MSVCRT.LIB | Import library for MSVCRT.DLL, retail version |
Return Value
_vsnprintf and _vsnwprintf return the number of characters written, not including the terminating null character, or a negative value if an output error occurs. For _vsnprintf, if the number of bytes to write exceeds buffer, then count bytes are written and –1 is returned.
Parameters
buffer
Storage ___location for output
count
Maximum number of characters to write
format
Format specification
argptr
Pointer to list of arguments
Remarks
Each of these functions takes a pointer to an argument list, then formats and writes the given data to the memory pointed to by buffer.
Generic-Text Routine Mappings
| TCHAR.H Routine | _UNICODE & _MBCS Not Defined | _MBCS Defined | _UNICODE Defined |
| _vsntprintf | _vsnprintf | _vsnprintf | _vsnwprintf |