lfs-book-zh_CN/chapter04/addinguser.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-tools-addinguser">
  <?dbhtml filename="addinguser.html"?>

  <title>Adding the LFS User</title>

  <para>When logged in as user <systemitem class="username">root</systemitem>,
  making a single mistake can damage or destroy a system. Therefore, we
  recommend building the packages in this chapter as an unprivileged user.
  You could use your own user name, but to make it easier to set up a clean
  working environment, create a new user called <systemitem
  class="username">lfs</systemitem> as a member of a new group (also named
  <systemitem class="groupname">lfs</systemitem>) and use this user during
  the installation process. As <systemitem class="username">root</systemitem>,
  issue the following commands to add the new user:</para>

<screen><userinput>groupadd lfs
useradd -s /bin/bash -g lfs -m -k /dev/null lfs</userinput></screen>

  <variablelist>
    <title>The meaning of the command line options:</title>

    <varlistentry>
      <term><parameter>-s /bin/bash</parameter></term>
      <listitem>
        <para>This makes <command>bash</command> the default shell for user
        <systemitem class="username">lfs</systemitem>.</para>
      </listitem>
    </varlistentry>

    <varlistentry>
      <term><parameter>-g lfs</parameter></term>
      <listitem>
        <para>This option adds user <systemitem class="username">lfs</systemitem>
        to group <systemitem class="groupname">lfs</systemitem>.</para>
      </listitem>
    </varlistentry>

    <varlistentry>
      <term><parameter>-m</parameter></term>
      <listitem>
        <para>This creates a home directory for <systemitem
        class="username">lfs</systemitem>.</para>
      </listitem>
    </varlistentry>

    <varlistentry>
      <term><parameter>-k /dev/null</parameter></term>
      <listitem>
        <para>This parameter prevents possible copying of files from a skeleton
        directory (default is <filename class="directory">/etc/skel</filename>)
        by changing the input location to the special null device.</para>
      </listitem>
    </varlistentry>

    <varlistentry>
      <term><parameter>lfs</parameter></term>
      <listitem>
        <para>This is the actual name for the created group and user.</para>
      </listitem>
    </varlistentry>

  </variablelist>

  <para>To log in as <systemitem class="username">lfs</systemitem> (as opposed
  to switching to user <systemitem class="username">lfs</systemitem> when logged
  in as <systemitem class="username">root</systemitem>, which does not require
  the <systemitem class="username">lfs</systemitem> user to have a password),
  give <systemitem class="username">lfs</systemitem> a password:</para>

<screen role="nodump"><userinput>passwd lfs</userinput></screen>

  <para>Grant <systemitem class="username">lfs</systemitem> full access to
  <filename class="directory">$LFS/tools</filename> by making
  <systemitem class="username">lfs</systemitem> the directory owner:</para>

<screen><userinput>chown -v lfs $LFS/tools</userinput></screen>

  <para>If a separate working directory was created as suggested, give
  user <systemitem class="username">lfs</systemitem> ownership of this
  directory:</para>

<screen><userinput>chown -v lfs $LFS/sources</userinput></screen>

  <para>Next, login as user <systemitem class="username">lfs</systemitem>.
  This can be done via a virtual console, through a display manager, or with
  the following substitute user command:</para>

<screen role="nodump"><userinput>su - lfs</userinput></screen>

  <para>The <quote><parameter>-</parameter></quote> instructs
  <command>su</command> to start a login shell as opposed to a non-login shell.
  The difference between these two types of shells can be found in detail in
  <filename>bash(1)</filename> and <command>info bash</command>.</para>

</sect1>