const io/fs.ModeSocket

3 uses

	io/fs (current package)
		fs.go#L182: 	ModeSocket                                     // S: Unix domain socket
		fs.go#L190: 	ModeType = ModeDir | ModeSymlink | ModeNamedPipe | ModeSocket | ModeDevice | ModeCharDevice | ModeIrregular

	os
		types.go#L45: 	ModeSocket     = fs.ModeSocket     // S: Unix domain socket