From e8afce4d2db73800639a11a957502963150253c2 Mon Sep 17 00:00:00 2001
From: Xi Ruoyao <xry111@xry111.site>
Date: Wed, 22 Jun 2022 15:12:06 +0800
Subject: [PATCH] bc: enable readline

Using readline can improve line editing feature of bc, but it's not
enabled by default.

As readline is already installed before bc, let's pick up this
improvement with no cost.
---
 appendices/dependencies.xml |  4 ++--
 chapter08/bc.xml            | 16 ++++++++++++----
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/appendices/dependencies.xml b/appendices/dependencies.xml
index 3398a2950..7103c3250 100644
--- a/appendices/dependencies.xml
+++ b/appendices/dependencies.xml
@@ -244,7 +244,7 @@
       <segmentedlist id="bc-depends">
         <segtitle>&dependencies;</segtitle>
         <seglistitem>
-          <seg>Bash, Binutils, Coreutils, GCC, Glibc, Grep, and Make</seg>
+          <seg>Bash, Binutils, Coreutils, GCC, Glibc, Grep, Make, and Readline</seg>
         </seglistitem>
       </segmentedlist>
 
@@ -2652,7 +2652,7 @@
       <segmentedlist id="readline-before">
         <segtitle>&before;</segtitle>
         <seglistitem>
-          <seg>Bash and Gawk</seg>
+          <seg>Bash, Bc, and Gawk</seg>
         </seglistitem>
       </segmentedlist>
 
diff --git a/chapter08/bc.xml b/chapter08/bc.xml
index 9678ddd54..4493f8219 100644
--- a/chapter08/bc.xml
+++ b/chapter08/bc.xml
@@ -43,7 +43,7 @@
 
     <para>Prepare Bc for compilation:</para>
 
-<screen><userinput remap="configure">CC=gcc ./configure --prefix=/usr -G -O3</userinput></screen>
+<screen><userinput remap="configure">CC=gcc ./configure --prefix=/usr -G -O3 -r</userinput></screen>
 
     <variablelist>
       <title>The meaning of the configure options:</title>
@@ -55,6 +55,14 @@
         </listitem>
       </varlistentry>
 
+      <varlistentry>
+        <term><parameter>-G</parameter></term>
+        <listitem>
+          <para>Omit parts of the test suite that won't work
+          without a GNU bc present.</para>
+        </listitem>
+      </varlistentry>
+
       <varlistentry>
         <term><parameter>-O3</parameter></term>
         <listitem>
@@ -63,10 +71,10 @@
       </varlistentry>
 
       <varlistentry>
-        <term><parameter>-G</parameter></term>
+        <term><parameter>-r</parameter></term>
         <listitem>
-          <para>Omit  parts of the test suite that won't work
-          without a GNU bc present.</para>
+          <para>Enable the use of <application>Readline</application> to
+          improve the line editing feature of bc.</para>
         </listitem>
       </varlistentry>
     </variablelist>