diff -r ffbbe25dab09 -r e44e98fe9de8 core/src/luan/modules/IoLuan.java
--- a/core/src/luan/modules/IoLuan.java	Tue Jun 14 00:04:08 2016 -0600
+++ b/core/src/luan/modules/IoLuan.java	Tue Jun 14 17:54:12 2016 -0600
@@ -582,6 +582,7 @@
 			add( schemes, "https", LuanState.class, String.class, LuanTable.class );
 			add( schemes, "luan", LuanState.class, String.class );
 			add( schemes, "stdin", LuanState.class );
+			add( schemes, "os", String.class );
 		} catch(NoSuchMethodException e) {
 			throw new RuntimeException(e);
 		}
@@ -669,6 +670,74 @@
 	}
 
 
+	public static final class LuanOs extends LuanIO {
+		private final Process proc;
+
+		private LuanOs(String cmd) throws IOException {
+			this.proc = Runtime.getRuntime().exec(cmd);
+		}
+
+		@Override public InputStream inputStream() throws IOException {
+			return proc.getInputStream();
+		}
+
+		@Override OutputStream outputStream() throws IOException {
+			return proc.getOutputStream();
+		}
+
+		@Override public String to_string() {
+			return proc.toString();
+		}
+
+		@Override public String to_uri_string() {
+			throw new UnsupportedOperationException();
+		}
+
+		@Override public boolean exists() {
+			return true;
+		}
+
+		public void wait_for()
+			throws IOException, LuanException
+		{
+			try {
+				proc.waitFor();
+			} catch(InterruptedException e) {
+				throw new RuntimeException(e);
+			}
+			int exitVal = proc.exitValue();
+			if( exitVal != 0 ) {
+				Reader err = new InputStreamReader(proc.getErrorStream());
+				String error = Utils.readAll(err);
+				err.close();
+				throw new LuanException(error);
+			}
+		}
+
+		@Override public String read_text() throws IOException, LuanException {
+			String s = super.read_text();
+			wait_for();
+			return s;
+		}
+
+		@Override public LuanTable table() {
+			LuanTable tbl = super.table();
+			try {
+				tbl.rawPut( "wait_for", new LuanJavaFunction(
+					LuanOs.class.getMethod( "wait_for" ), this
+				) );
+			} catch(NoSuchMethodException e) {
+				throw new RuntimeException(e);
+			}
+			return tbl;
+		}
+	}
+
+	public static LuanTable os(String cmd) throws IOException {
+		return new LuanOs(cmd).table();
+	}
+
+
 	public static String ip(String domain) {
 		try {
 			return InetAddress.getByName(domain).getHostAddress();

diff -r ffbbe25dab09 -r e44e98fe9de8 core/src/luan/modules/Utils.java
--- a/core/src/luan/modules/Utils.java	Tue Jun 14 00:04:08 2016 -0600
+++ b/core/src/luan/modules/Utils.java	Tue Jun 14 17:54:12 2016 -0600
@@ -152,6 +152,7 @@
 
 
 
+/*	replace by uri"os:..."
 
 	// process
 
@@ -195,5 +196,5 @@
 		checkProcess(proc);
 		return s;
 	}
-
+*/
 }