update docguide.sgml , ecpg.sgml and extend.sgml

Author: chegong18

postgresql/doc/src/sgml/docguide.sgml

@@ -274,14 +274,18 @@ ____________________________________________________________________________-->
    You can get away with not installing DocBook XML and the DocBook XSLT
    stylesheets locally, because the required files will be downloaded from the
    Internet and cached locally.  This may in fact be the preferred solution if
-   your operating system packages provide only an old version of especially
-   the stylesheets or if no packages are available at all.  See
-   the <option>-&minus;nonet</option> option for <command>xmllint</command>
-   and <command>xsltproc</command> for more information.
+   your operating system packages provide only an old version of these files,
+   or if no packages are available at all.
+   If you want to prevent any attempt to access the Internet while building
+   the documentation, you need to pass the <option>--nonet</option> option
+   to <command>xmllint</command> and <command>xsltproc</command>; see below
+   for an example.
   </para>
 ____________________________________________________________________________-->
   <para>
-   你可以在本地不安装DocBook XML和DocBook XSLT样式表的情况下开始工作，因为所需的文件将从Internet下载下来并且缓存在本地。如果你的操作系统包仅提供了旧版本的样式表或者根本就没有所需的包，那么这种方式实际上是最好的解决方案。更多信息请见<command>xmllint</command>和<command>xsltproc</command>的<option>--nonet</option>选项。
+   你可以在本地不安装DocBook XML和DocBook XSLT样式表的情况下开始工作，因为所需的文件将从Internet下载下来并且缓存在本地。
+   如果你的操作系统包仅提供了这些文件的旧版本或者根本就没有所需的包，那么这种方式实际上是最好的解决方案。
+   如果你想要防止任何访问互联网的尝试，在构建文档的时候，你需要传递<option>--nonet</option> 选项到 <command>xmllint</command> 和 <command>xsltproc</command>;参见下方示例。
   </para>
 
   <sect2>
@@ -412,33 +416,63 @@ ____________________________________________________________________________-->
 <!--==========================orignal english content==========================
   <para>
    Before you can build the documentation you need to run the
-   <filename>configure</filename> script as you would when building
+   <filename>configure</filename> script, as you would when building
    the <productname>PostgreSQL</productname> programs themselves.
-   Check the output near the end of the run, it should look something
+   Check the output near the end of the run; it should look something
    like this:
 <screen>
 checking for xmllint... xmllint
-checking for DocBook XML V4.5... yes
-checking for dbtoepub... dbtoepub
 checking for xsltproc... xsltproc
 checking for fop... fop
+checking for dbtoepub... dbtoepub
 </screen>
-   If <filename>xmllint</filename> was not found then some of the following
-   tests will be skipped.
+   If <filename>xmllint</filename> or <filename>xsltproc</filename> is not
+   found, you will not be able to build any of the documentation.
+   <filename>fop</filename> is only needed to build the documentation in
+   PDF format.
+   <filename>dbtoepub</filename> is only needed to build the documentation
+   in EPUB format.
   </para>
 ____________________________________________________________________________-->
   <para>
-   在你能编译文档之前，你需要运行<filename>configure</filename>脚本，就像你在编译<productname>PostgreSQL</productname>程序本身时所作的那样。检查运行末尾附近的输出，应该看起来像这样：
+   在你能编译文档之前，你需要运行<filename>configure</filename>脚本，就像你在编译<productname>PostgreSQL</productname>程序本身时所作的那样。
+   检查运行末尾附近的输出；应该看起来像这样：
 <screen>
 checking for xmllint... xmllint
-checking for DocBook XML V4.5... yes
-checking for dbtoepub... dbtoepub
 checking for xsltproc... xsltproc
 checking for fop... fop
+checking for dbtoepub... dbtoepub
 </screen>
-   如果没有找到<filename>xmllint</filename>，那么一些后续测试将被跳过。
+   如果没有找到<filename>xmllint</filename> 或 <filename>xsltproc</filename>，你将不能构建任何文档。
+   <filename>fop</filename>仅在构建PDF格式的文档时需要。
+   <filename>dbtoepub</filename>仅在构建EPUB格式的文档时需要。
   </para>
 
+<!--==========================orignal english content==========================
+  <para>
+   If necessary, you can tell <filename>configure</filename> where to find
+   these programs, for example
+<screen>
+./configure ... XMLLINT=/opt/local/bin/xmllint ...
+</screen>
+   Also, if you want to ensure that <filename>xmllint</filename>
+   and <filename>xsltproc</filename> will not perform any network access,
+   you can do something like
+<screen>
+./configure ... XMLLINT="xmllint -&minus;nonet" XSLTPROC="xsltproc -&minus;nonet" ...
+</screen>
+  </para>
+____________________________________________________________________________-->
+  <para>
+   如果需要，你可以告知 <filename>configure</filename> 在哪里发现这些程序，例如
+<screen>
+./configure ... XMLLINT=/opt/local/bin/xmllint ...
+</screen>
+   此外，如果你想要确定 <filename>xmllint</filename> 和 <filename>xsltproc</filename> 将不会执行任何网络访问,你可以像这样做
+<screen>
+./configure ... XMLLINT="xmllint --nonet" XSLTPROC="xsltproc --nonet" ...
+</screen>
+  </para>
   </sect2>
  </sect1>