Returns the credentials of the foreign process connected to this socket, if any (e.
g. it is only supported for g_socket_family_unix sockets).
If this operation isn't supported on the OS, the method fails with the g_io_error_not_supported error. On Linux this is implemented by reading the so_peercred option on the underlying socket.
This method can be expected to be available on the following platforms:
- Linux since GLib 2.26
- OpenBSD since GLib 2.30
- Solaris, Illumos and OpenSolaris since GLib 2.40
- NetBSD since GLib 2.42
- macOS, tvOS, iOS since GLib 2.66
Other ways to obtain credentials from a foreign peer includes the
GUnixCredentialsMessage type and