devela::_dep::sdl3::sys::asyncio

Function SDL_AsyncIOFromFile

pub unsafe extern "C" fn SDL_AsyncIOFromFile(
    file: *const i8,
    mode: *const i8,
) -> *mut SDL_AsyncIO
Available on crate feature dep_sdl3 only.
Expand description

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

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.

§Parameters

  • file: a UTF-8 string representing the filename to open.
  • mode: an ASCII string representing the mode to be used for opening the file.

§Return value

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

§Availability

This function is available since SDL 3.2.0.

§See also