first commit

user/ln.c

@@ -0,0 +1,15 @@
+#include "kernel/types.h"
+#include "kernel/stat.h"
+#include "user/user.h"
+
+int
+main(int argc, char *argv[])
+{
+  if(argc != 3){
+    fprintf(2, "Usage: ln old new\n");
+    exit(1);
+  }
+  if(link(argv[1], argv[2]) < 0)
+    fprintf(2, "link %s %s: failed\n", argv[1], argv[2]);
+  exit(0);
+}