# SDL_IOvprintf

Print to an [SDL_IOStream](SDL_IOStream) data stream.

## Header File

Defined in [<SDL3/SDL_iostream.h>](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_iostream.h)

## Syntax

```c
size_t SDL_IOvprintf(SDL_IOStream *context, const char *fmt, va_list ap);
```

## Function Parameters

|                                |             |                                                         |
| ------------------------------ | ----------- | ------------------------------------------------------- |
| [SDL_IOStream](SDL_IOStream) * | **context** | a pointer to an [SDL_IOStream](SDL_IOStream) structure. |
| const char *                   | **fmt**     | a printf() style format string.                         |
| va_list                        | **ap**      | a variable argument list.                               |

## Return Value

(size_t) Returns the number of bytes written or 0 on failure; call
[SDL_GetError](SDL_GetError)() for more information.

## Remarks

This function does formatted printing to the stream.

## Thread Safety

This function is not thread safe.

## Version

This function is available since SDL 3.2.0.

## See Also

- [SDL_IOprintf](SDL_IOprintf)
- [SDL_WriteIO](SDL_WriteIO)

----
[CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryIOStream](CategoryIOStream)