/usr/share/hyphy/TreeAddIns/Splits is in hyphy-common 2.2.6+dfsg-3build3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 | _astavl_ = ACCEPT_ROOTED_TREES;
ACCEPT_ROOTED_TREES = 1;
Topology _ast_ = _TREE_STRING_FOR_PROCESSING_;
ACCEPT_ROOTED_TREES = _astavl_;
/* obtain an AVL data structure of the tree, post-order layout */
_astavl_  = _ast_^1;
_tree_size_ = Abs (_astavl_);
for (_a_node = 2; _a_node < _tree_size_; _a_node = _a_node + 1)
{
	_node_info = _astavl_[_a_node];
	myDegree = Abs(_node_info["Children"]);
	myDepth  = _node_info["Depth"];
	
	if (myDegree)
	{
		nodeName = _node_info["Name"];
		fprintf (stdout, "\n", nodeName, ":");
		for (_b_node = _a_node + 1; _b_node < _tree_size_; _b_node = _b_node + 1)
		{
			_bnode_info = _astavl_[_b_node];
			if (_bnode_info["Depth"] <= myDepth)
			{
				break;
			}
			if (Abs(_bnode_info["Children"])==0)
			{
				_bnode_info = _bnode_info["Name"];
				fprintf (stdout, "\t", _bnode_info);
			}
		}
	}
}
fprintf (stdout, "\n");
 |