lfs-book/chapter06/flex.xml

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<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
  <!ENTITY % general-entities SYSTEM "../general.ent">
  %general-entities;
]>

<sect1 id="ch-system-flex" role="wrap">
  <?dbhtml filename="flex.html"?>

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

  <title>Flex-&flex-version;</title>

  <indexterm zone="ch-system-flex">
    <primary sortas="a-Flex">Flex</primary>
  </indexterm>

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

    <para>The Flex package contains a utility for generating programs that
    recognize patterns in text.</para>

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

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

  </sect2>

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

    <para>First, fix a problem introduced with glibc-2.26:</para>

<screen><userinput remap="pre">sed -i "/math.h/a #include &lt;malloc.h&gt;" src/flexdef.h</userinput></screen>

    <para>The build procedure assumes the <application>help2man</application>
    program is available to create a man page from the executable --help option.
    This is not present, so we use an environment variable to skip this process.
    Now, prepare Flex for compilation:</para>

<screen><userinput remap="configure">HELP2MAN=/tools/bin/true \
./configure --prefix=/usr --docdir=/usr/share/doc/flex-&flex-version;</userinput></screen>

    <para>Compile the package:</para>

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

    <para>To test the results (about 0.5 SBU), issue:</para>

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

    <para>Install the package:</para>

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

    <para>A few programs do not know about <command>flex</command> yet and
    try to run its predecessor, <command>lex</command>. To support those
    programs, create a symbolic link named <filename>lex</filename> that
    runs <filename>flex</filename> in <command>lex</command> emulation
    mode:</para>

<screen><userinput remap="install">ln -sv flex /usr/bin/lex</userinput></screen>

  </sect2>

  <sect2 id="contents-flex" role="content">
    <title>Contents of Flex</title>

    <segmentedlist>
      <segtitle>Installed programs</segtitle>
      <segtitle>Installed libraries</segtitle>
      <segtitle>Installed directory</segtitle>

      <seglistitem>
        <seg>flex, flex++ (link to flex), and lex (link to flex)</seg>
        <seg>libfl.so</seg>
        <seg>/usr/share/doc/flex-&flex-version;</seg>
      </seglistitem>
    </segmentedlist>

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

      <varlistentry id="flex">
        <term><command>flex</command></term>
        <listitem>
          <para>A tool for generating programs that recognize patterns in text;
          it allows for the versatility to specify the rules for pattern-finding,
          eradicating the need to develop a specialized program</para>
          <indexterm zone="ch-system-flex flex">
            <primary sortas="b-flex">flex</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="flexpp">
        <term><command>flex++</command></term>
        <listitem>
          <para>An extension of flex, is used for generating C++ code
          and classes. It is a symbolic link to <command>flex</command></para>
          <indexterm zone="ch-system-flex flexpp">
            <primary sortas="b-flex++">flex++</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="lex">
        <term><command>lex</command></term>
        <listitem>
          <para>A symbolic link that runs <command>flex</command> in
          <command>lex</command> emulation mode</para>
          <indexterm zone="ch-system-flex lex">
            <primary sortas="b-lex">lex</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="libfl">
        <term><filename class="libraryfile">libfl</filename></term>
        <listitem>
          <para>The <filename class="libraryfile">flex</filename> library</para>
          <indexterm zone="ch-system-flex libfl">
            <primary sortas="c-libfl">libfl</primary>
          </indexterm>
        </listitem>
      </varlistentry>

    </variablelist>

  </sect2>

</sect1>