1 files changed, 5 insertions, 0 deletions
diff --git a/doio.c b/doio.c
index a551d05819..70b35359c4 100644
--- a/doio.c
+++ b/doio.c
@@ -15,6 +15,11 @@
  * chattering, into calmer and more level reaches."
  */
 
+/* This file contains functions that do the actual I/O on behalf of ops.
+ * For example, pp_print() calls the do_print() function in this file for
+ * each argument needing printing.
+ */
+
 #include "EXTERN.h"
 #define PERL_IN_DOIO_C
 #include "perl.h"