Check for stdin and args

1 files changed, 6 insertions, 0 deletions

diff --git a/ponysay b/ponysay
index 345dd0e..e07e1e3 100755
--- a/ponysay
+++ b/ponysay
@@ -45,6 +45,12 @@ Options:
 EOF
 }
 
+# if no stdin and no argumrnts then print usage and exit
+if [[ -t 0 && $# == 0 ]]; then
+  usage
+  exit
+fi
+
 say() {
     # Ponies use UTF-8 drawing characters. Prevent a Perl warning.
     export PERL_UNICODE=S