Index: trunk/Ohana/src/opihi/cmd.basic/scan.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.basic/scan.c	(revision 7917)
+++ trunk/Ohana/src/opihi/cmd.basic/scan.c	(revision 14179)
@@ -23,6 +23,11 @@
   ALLOCATE (line, char, 1024);
   N = 1;
-  if (argc == 4) 
+  if (argc == 4) {
     N = atof(argv[3]);
+    if (N < 1) {
+      gprint (GP_ERR, "scan: line numbers must start at 1\n");
+      return (FALSE);
+    }
+  }
 
   for (i = 0; (i < N) && ((status = scan_line (f, line)) != EOF); i++);