lfs-book-zh_CN/chapter06/bc.xml

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  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
  <!ENTITY % general-entities SYSTEM "../general.ent">
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<sect1 id="ch-system-bc" role="wrap">
  <?dbhtml filename="bc.html"?>

  <sect1info condition="script">
    <productname>bc</productname>
    <productnumber>&bc-version;</productnumber>
    <address>&bc-url;</address>
  </sect1info>

  <title>Bc-&bc-version;</title>

  <indexterm zone="ch-system-bc">
    <primary sortas="a-Bc">Bc</primary>
  </indexterm>

  <sect2 role="package">
    <title/>

    <para>The Bc package contains an arbitrary precision numeric processing 
    language.</para>

    <segmentedlist>
      <segtitle>&buildtime;</segtitle>
      <segtitle>&diskspace;</segtitle>

      <seglistitem>
        <seg>&bc-ch6-sbu;</seg>
        <seg>&bc-ch6-du;</seg>
      </seglistitem>
    </segmentedlist>

  </sect2>

  <sect2 role="installation">
    <title>Installation of Bc</title>

    <para>First, change an internal script to use <command>sed</command> instead 
    of <command>ed</command>:</para>

<screen><userinput remap="pre">cat &gt; bc/fix-libmath_h &lt;&lt; "EOF"
#! /bin/bash
sed -e '1   s/^/{"/' \
    -e     's/$/",/' \
    -e '2,$ s/^/"/'  \
    -e   '$ d'       \
    -i libmath.h

sed -e '$ s/$/0}/' \
    -i libmath.h
EOF</userinput></screen> 

    <para>Create a temporary symbolic link so the package can find
    the readline library and confirm that its required libncurses
    library is available. Even though the libraries are in /tools/lib
    at this point, the system will use /usr/lib at the end of
    this chapter.</para>

<screen><userinput remap="pre">ln -sv /tools/lib/libncursesw.so /usr/lib/libncurses.so</userinput></screen>

    <para>Prepare Bc for compilation:</para>

<screen><userinput remap="configure">./configure --prefix=/usr           \
            --with-readline         \
            --mandir=/usr/share/man \
            --infodir=/usr/share/info</userinput></screen>

    <variablelist>
      <title>The meaning of the configure options:</title>

      <varlistentry>
        <term><parameter>--with-readline</parameter></term>
        <listitem>
          <para>This option tells Bc to use the <filename
          class="libraryfile">readline</filename> library that is already
          installed on the system rather than using its own readline
          version.</para>
        </listitem>
      </varlistentry>

    </variablelist>

    <para>Compile the package:</para>

<screen><userinput remap="make">make</userinput></screen>

    <para>To test bc, run the commands below. There is quite a bit of output,
    so you may want to redirect it to a file. There are a very small percentage
    of tests (10 of 12,144) that will indicate a round off error at the last
    digit.</para>

<screen><userinput remap="test">echo "quit" | ./bc/bc -l Test/checklib.b</userinput></screen>

    <para>Install the package:</para>

<screen><userinput remap="install">make install</userinput></screen>

  </sect2>

  <sect2 id="contents-bc" role="content">
    <title>Contents of Bc</title>

    <segmentedlist>
      <segtitle>Installed programs</segtitle>

      <seglistitem>
        <seg>bc and dc</seg>
      </seglistitem>
    </segmentedlist>

    <variablelist>
      <bridgehead renderas="sect3">Short Descriptions</bridgehead>
      <?dbfo list-presentation="list"?>
      <?dbhtml list-presentation="table"?>

      <varlistentry id="bc">
        <term><command>bc</command></term>
        <listitem>
          <para>is a command line calculator</para>
          <indexterm zone="ch-system-bc bc">
            <primary sortas="b-bc">bc</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="dc">
        <term><command>dc</command></term>
        <listitem>
          <para>is a reverse-polish command line calculator</para>
          <indexterm zone="ch-system-bc dc">
            <primary sortas="b-dc">dc</primary>
          </indexterm>
        </listitem>
      </varlistentry>

    </variablelist>

  </sect2>

</sect1>