1 files changed, 3 insertions, 0 deletions
diff --git a/example/ivyprobe.pl b/example/ivyprobe.pl
index 199c6e9..41efe78 100755
--- a/example/ivyprobe.pl
+++ b/example/ivyprobe.pl
@@ -114,6 +114,9 @@ $Ivyobj->start;
 
 sub cb {
     my $line = <STDIN>;
+    unless (defined $line) {
+      die "readline mode problem : try $0 -stdio\n";
+    }
     chomp $line;
     exit if (&interpret_line ($line));
 }