--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/uprogs/echo.c	Sun Jan 06 19:27:03 2019 +0900
@@ -0,0 +1,13 @@
+#include "types.h"
+#include "stat.h"
+#include "user.h"
+
+int
+main(int argc, char *argv[])
+{
+  int i;
+
+  for(i = 1; i < argc; i++)
+    printf(1, "%s%s", argv[i], i+1 < argc ? " " : "\n");
+  exit();
+}