lfs-book-zh_CN/appendixa/ed-desc.xml

<sect2><title>&nbsp;</title><para>&nbsp;</para></sect2>

<sect2><title>Short descriptions</title>

<para><command>ed</command> is a line-oriented text editor. It can be used
to create, display, modify and otherwise manipulate text files.</para>

<para><command>red</command> is a restricted ed -- it can only edit files
in the current directory and cannot execute shell commands.</para>

</sect2>