Seek within an SDL_RWops data stream.
Sint64 SDL_RWseek(SDL_RWops *context, Sint64 offset, int whence);| context | a pointer to an SDL_RWops structure |
| offset | an offset in bytes, relative to whence location; can be negative |
| whence | any of SDL_RW_SEEK_SET, SDL_RW_SEEK_CUR, SDL_RW_SEEK_END |
Returns the final offset in the data stream after the seek or a negative error code on failure; call SDL_GetError() for more information.
This function seeks to byte offset, relative to whence.
whence may be any of the following values:
SDL_RW_SEEK_SET: seek from the beginning of dataSDL_RW_SEEK_CUR: seek relative to current read pointSDL_RW_SEEK_END: seek relative to the end of dataIf this stream can not seek, it will return -1.
SDL_RWseek() is actually a wrapper function that calls the SDL_RWops's seek method appropriately, to simplify application development.
This function is available since SDL 3.0.0.
SDL_RWops *rw = SDL_RWFromFile("myfile.bin", "rb");
if (rw != NULL) {
/* Seek to 0 bytes from the end of the file */
Sint64 length = SDL_RWseek(rw, 0, SDL_RW_SEEK_END);
SDL_RWclose(rw);
if (length < 0) {
printf("Could not seek inside myfile.bin\n");
} else {
printf("myfile.bin is %d bytes long\n", length);
}
}