--- a/src/luan/modules/IoLuan.java	Mon Jun 17 21:50:40 2019 -0600
+++ b/src/luan/modules/IoLuan.java	Tue Jun 18 16:27:03 2019 -0600
@@ -134,9 +134,11 @@
 	}
 
 
-	private static File objToFile(Object obj) {
+	private static File objToFile(Luan luan,Object obj) throws LuanException {
 		if( obj instanceof String ) {
-			return new File((String)obj);
+			String fileName = (String)obj;
+			check(luan,"file:"+fileName);
+			return new File(fileName);
 		}
 		if( obj instanceof LuanTable ) {
 			LuanTable t = (LuanTable)obj;
@@ -444,14 +446,28 @@
 			return file.exists();
 		}
 
-		public void rename_to(Object destObj) throws LuanException {
-			File dest = objToFile(destObj);
+		public void rename_to(Luan luan,Object destObj) throws LuanException {
+			File dest = objToFile(luan,destObj);
 			if( dest==null )
-				throw new LuanException( "bad argument #1 to 'objToFile' (string or file table expected)" );
+				throw new LuanException( "bad argument #1 to 'rename_to' (string or file table expected)" );
 			if( !file.renameTo(dest) )
 				throw new LuanException("couldn't rename file "+file+" to "+dest);
 		}
 
+		public void link_to(Luan luan,Object destObj) throws LuanException, IOException {
+			File dest = objToFile(luan,destObj);
+			if( dest==null )
+				throw new LuanException( "bad argument #1 to 'link_to' (string or file table expected)" );
+			Files.createLink( file.toPath(), dest.toPath() );
+		}
+
+		public void symlink_to(Luan luan,Object destObj) throws LuanException, IOException {
+			File dest = objToFile(luan,destObj);
+			if( dest==null )
+				throw new LuanException( "bad argument #1 to 'symlink_to' (string or file table expected)" );
+			Files.createSymbolicLink( file.toPath(), dest.toPath() );
+		}
+
 		public LuanFile canonical(Luan luan) throws LuanException, IOException {
 			return new LuanFile(luan,file.getCanonicalFile());
 		}
@@ -535,13 +551,13 @@
 		final File dir;
 		Process proc;
 
-		private BaseOs(String cmd,LuanTable options) throws IOException, LuanException {
+		private BaseOs(Luan luan,String cmd,LuanTable options) throws IOException, LuanException {
 			this.cmd = cmd;
 			File dir = null;
 			if( options != null ) {
 				Map map = options.asMap();
 				Object obj = map.remove("dir");
-				dir = objToFile(obj);
+				dir = objToFile(luan,obj);
 				if( dir==null )
 					throw new LuanException( "bad option 'dir' (string or file table expected)" );
 				if( !map.isEmpty() )
@@ -596,7 +612,7 @@
 
 	public static final class LuanOs extends BaseOs {
 		public LuanOs(Luan luan,String cmd,LuanTable options) throws IOException, LuanException {
-			super(cmd,options);
+			super(luan,cmd,options);
 			check(luan,"os:"+cmd);
 			this.proc = Runtime.getRuntime().exec(cmd,null,dir);
 		}
@@ -604,7 +620,7 @@
 
 	public static final class LuanBash extends BaseOs {
 		public LuanBash(Luan luan,String cmd,LuanTable options) throws IOException, LuanException {
-			super(cmd,options);
+			super(luan,cmd,options);
 			check(luan,"bash:"+cmd);
 			this.proc = Runtime.getRuntime().exec(new String[]{"bash","-c",cmd},null,dir);
 		}