X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fdocs%2Fusers_guide%2Fghci.sgml;h=3e900c4b33a25f27c002c1f96cf14c0edd5f9ddb;hb=accc1381a865f51ad866e6b7c4bc927f1b7aacb7;hp=6c65538105b9cad2474cf64261477279492b9f4f;hpb=de3d76441c7f1366692c33027059b1a3f7999bc2;p=ghc-hetmet.git

diff --git a/ghc/docs/users_guide/ghci.sgml b/ghc/docs/users_guide/ghci.sgml
index 6c65538..3e900c4 100644
--- a/ghc/docs/users_guide/ghci.sgml
+++ b/ghc/docs/users_guide/ghci.sgml
@@ -525,7 +525,7 @@ Wed Mar 14 12:23:13 GMT 2001
     </sect2>
   </sect1>
 
-  <sect1>
+  <sect1 id="ghci-invokation">
     <title>Invoking GHCi</title>
     <indexterm><primary>invoking</primary><secondary>GHCi</secondary></indexterm>
     <indexterm><primary><option>--interactive</option></primary></indexterm>
@@ -1109,8 +1109,31 @@ Prelude> :set -fno-glasgow-exts
 	  properly with GHC's concurrency model.</para>
 	</listitem>
       </varlistentry>
-    </variablelist>
 
+      <varlistentry>
+	<term>After using <literal>getContents</literal>, I can't use
+	<literal>stdin</literal> again until I do
+	<literal>:load</literal> or <literal>:reload</literal>.</term>
+
+	<listitem>
+	  <para>This is the defined behaviour of
+	  <literal>getContents</literal>: it puts the stdin Handle in
+	  a state known as <firstterm>semi-closed</firstterm>, wherein
+	  any further I/O operations on it are forbidden.  Because I/O
+	  state is retained between computations, the semi-closed
+	  state persists until the next <literal>:load</literal> or
+	  <literal>:reload</literal> command.</para>
+
+	  <para>You can make <literal>stdin</literal> reset itself
+	  after every evaluation by giving GHCi the command
+	  <literal>:set +r</literal>.  This works because
+	  <literal>stdin</literal> is just a top-level expression that
+	  can be reverted to its unevaluated state in the same way as
+	  any other top-level expression (CAF).</para>
+	</listitem>
+      </varlistentry>
+
+    </variablelist>
   </sect1>
 
 </chapter>