GFileInputStream that
can be used to read the contents of the file.gFileRead(object, cancellable = NULL, .errwarn = TRUE)objectGFile to read.cancellableGFileInputStream] GFileInputStream or NULL on error.errorGError, or NULLcancellable is not NULL, then the operation can be cancelled by
triggering the cancellable object from another thread. If the operation
was cancelled, the error G_IO_ERROR_CANCELLED will be returned.
If the file does not exist, the G_IO_ERROR_NOT_FOUND error will be returned.
If the file is a directory, the G_IO_ERROR_IS_DIRECTORY error will be returned.
Other errors are possible too, and depend on what kind of filesystem the file is on.