(This is the documentation for SDL3, which is the current stable version. SDL2 was the previous version!)

SDL_AsyncIOFromFile

Use this function to create a new SDL_AsyncIO object for reading from and/or writing to a named file.

Header File

Syntax

SDL_AsyncIO * SDL_AsyncIOFromFile(const char *file, const char *mode);

Function Parameters

const char *	file	a UTF-8 string representing the filename to open.
const char *	mode	an ASCII string representing the mode to be used for opening the file.

Return Value

(SDL_AsyncIO *) Returns a pointer to the SDL_AsyncIO structure that is created or NULL on failure; call SDL_GetError() for more information.

Remarks

The mode string understands the following values:

"r": Open a file for reading only. It must exist.
"w": Open a file for writing only. It will create missing files or truncate existing ones.
"r+": Open a file for update both reading and writing. The file must exist.
"w+": Create an empty file for both reading and writing. If a file with the same name already exists its content is erased and the file is treated as a new empty file.

There is no "b" mode, as there is only "binary" style I/O, and no "a" mode for appending, since you specify the position when starting a task.

This function supports Unicode filenames, but they must be encoded in UTF-8 format, regardless of the underlying operating system.

This call is not asynchronous; it will open the file before returning, under the assumption that doing so is generally a fast operation. Future reads and writes to the opened file will be async, however.

Version

This function is available since SDL 3.2.0.