lfs-book/appendixa/patch-desc.xml

<sect2><title>Contents of Patch</title>

<para>Last checked against version &patch-contversion;.</para>

<sect3><title>Program Files</title>
<para>patch</para></sect3>

<sect3><title>Descriptions</title>

<sect4><title>patch</title>
<para>The patch program modifies a file according to a patch file. A patch
file usually is a list, created by the diff program, that contains
instructions on how an original file needs to be modified. Patch is used
a lot for source code patches since it saves time and space. Imagine
a package that is 1 MB in size. The next version of that package
only has changes in two files of the first version. It can be shipped as an
entirely new package of 1 MB or just as a patch file of 1 KB, which will
update the first version to make it identical to the second version. So
if the first version was downloaded already, a patch file avoids
a second large download.</para></sect4>

</sect3>

</sect2>