[DOC] Mention "-" in ARGF

1 files changed, 7 insertions, 2 deletions

diff --git a/io.c b/io.c
index 480bed9157..712dce3ceb 100644
--- a/io.c
+++ b/io.c
@@ -14625,11 +14625,16 @@ set_LAST_READ_LINE(VALUE val, ID _x, VALUE *_y)
  *     ARGV.replace ["file2", "file3"]
  *     ARGF.read      # Returns the contents of file2 and file3
  *
- * If +ARGV+ is empty, ARGF acts as if it contained STDIN, i.e. the data
- * piped to your script. For example:
+ * If +ARGV+ is empty, ARGF acts as if it contained <tt>"-"</tt> that
+ * makes ARGF read from STDIN, i.e. the data piped or typed to your
+ * script. For example:
  *
  *     $ echo "glark" | ruby -e 'p ARGF.read'
  *     "glark\n"
+ *
+ *     $ echo Glark > file1
+ *     $ echo "glark" | ruby -e 'p ARGF.read' -- - file1
+ *     "glark\nGlark\n"
  */
 
 /*