/usr/sh4-linux-gnu/include/sys/socketvar.h is in libc6-dev-sh4-cross 2.23-0ubuntu3cross1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | /* This header is used on many systems but for GNU we have everything
already defined in the standard header. */
#include <sys/socket.h>
|