<?xml version="1.0"?>
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                              "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
<!ENTITY % entities.ent SYSTEM "entities.ent">
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<varlistentry>
<term><option>--enable-write18</option></term>
<listitem>
<indexterm>
<primary>--enable-write18</primary>
</indexterm>
<indexterm>
<primary>--shell-escape</primary>
</indexterm>
<indexterm>
<primary>\write18 (run a program from within &TeX;)</primary>
</indexterm>
<para>Fully enable the <markup
role="tex">\write18{<replaceable>command</replaceable>}</markup>
construct.  It is only partially enabled by default to avoid security
problems.  When fully enabled, the command (which undergoes the usual
&TeX; expansions) is passed to the command interpreter.  The output of
the command is not diverted anywhere, so it will not appear in the log
file.  The command execution either happens at <markup
role="tex">\output</markup> time or right away, according to the
absence or presence of the <markup role="tex">\immediate</markup>
prefix.</para></listitem>
</varlistentry>
