Cosmetic update to some comments.

libs/libc/stdio/lib_libvscanf.c

@@ -200,10 +200,11 @@ doexit:
  ****************************************************************************/
 
 /****************************************************************************
- * Name:  lib_vscanf
+ * Name: lib_vscanf
  *
  * Description:
- *    Stream-oriented version of vsscanf.
+ *  Stream-oriented implementation that underlies scanf family:  scanf,
+ *  fscanf, vfscanf, sscanf, and vsscanf
  *
  ****************************************************************************/
 

libs/libc/stdio/lib_libvsprintf.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * libs/libc/stdio/lib_libvsprintf.c
  *
- *   Copyright (C) 2007-2012, 2018 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2012, 2018-2019 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -1183,7 +1183,12 @@ static void postjustify(FAR struct lib_outstream_s *obj, uint8_t justify,
  ****************************************************************************/
 
 /****************************************************************************
- * libs/libc/stdio/lib_vsprintf
+ * Name: lib_vsprintf
+ *
+ * Description:
+ *  Stream-oriented implementation that underlies printf family:  printf,
+ *  fprint, sprint, etc.
+ *
  ****************************************************************************/
 
 int lib_vsprintf(FAR struct lib_outstream_s *obj, FAR const IPTR char *src,

libs/libc/stdio/lib_sscanf.c

@@ -48,7 +48,7 @@
  ****************************************************************************/
 
 /****************************************************************************
- * sscanf
+ * Name: sscanf
  ****************************************************************************/
 
 int sscanf(FAR const char *buf, FAR const IPTR char *fmt, ...)

libs/libc/stdio/lib_vfscanf.c

@@ -50,6 +50,10 @@
  * Public Functions
  ****************************************************************************/
 
+/****************************************************************************
+ * Name: vfscanf
+ ****************************************************************************/
+
 int vfscanf(FAR FILE *stream, FAR const IPTR char *fmt, va_list ap)
 {
   struct lib_stdinstream_s stdinstream;

libs/libc/stdio/lib_vsscanf.c

@@ -50,6 +50,10 @@
  * Public Functions
  ****************************************************************************/
 
+/****************************************************************************
+ * Name: vsscanf
+ ****************************************************************************/
+
 int vsscanf(FAR const char *buf, FAR const char *fmt, va_list ap)
 {
   struct lib_meminstream_s meminstream;