lfs-book-zh_CN/chapter04/addinguser.xml

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<sect1 id="ch-tools-addinguser">
<title>Adding the LFS User</title>
<?dbhtml filename="addinguser.html"?>

<para>When logged in as user <emphasis>root</emphasis>, 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
<emphasis>lfs</emphasis> as a member of a new group (also named
<emphasis>lfs</emphasis>) and use this user during the installation process. As
<emphasis>root</emphasis>, 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>

<para>The meaning of the command line options:</para>

<variablelist>
<varlistentry>
<term><parameter>-s /bin/bash</parameter></term>
<listitem><para>This makes
<command>bash</command> the default shell for user
<emphasis>lfs</emphasis>.</para></listitem>
</varlistentry>

<varlistentry>
<term><parameter>-g lfs</parameter></term>
<listitem><para>This option adds user <emphasis>lfs</emphasis> to group
<emphasis>lfs</emphasis>.</para></listitem>
</varlistentry>

<varlistentry>
<term><parameter>-m</parameter></term>
<listitem><para>This creates a home
directory for <emphasis>lfs</emphasis>.</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 <emphasis>lfs</emphasis> (as opposed to switching
to user <emphasis>lfs</emphasis> when
logged in as <emphasis>root</emphasis>, which does not require the
<emphasis>lfs</emphasis> user to have a
password), give <emphasis>lfs</emphasis> a password:</para>

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

<para>Grant <emphasis>lfs</emphasis> full access to
<filename class="directory">$LFS/tools</filename> by making
<emphasis>lfs</emphasis> 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 <emphasis>lfs</emphasis> ownership of this directory:</para>

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

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

<screen><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>