[rpm-guide] Add a paragraph explaining the syntax of scriptlets

[Jared Smith]

commit cc44b49e0977e4f50ae09f48b15b8367c59331de
Author: Jared K. Smith <jsmith at fedoraproject.org>
Date:   Fri Sep 6 08:27:50 2013 -0400

    Add a paragraph explaining the syntax of scriptlets

 en-US/rpm-guide-specfiles.xml |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)
---
diff --git a/en-US/rpm-guide-specfiles.xml b/en-US/rpm-guide-specfiles.xml
index 79e6fec..6e3fbb8 100644
--- a/en-US/rpm-guide-specfiles.xml
+++ b/en-US/rpm-guide-specfiles.xml
@@ -1380,6 +1380,20 @@
         and the %postun script just after the uninstall.
       </para>
       <para>
+        The basic syntax is similar to the <literal>%build</literal>,
+        <literal>%install</literal>, and other sections of the rpm spec file.
+      </para>
+      <para>
+        The scripts support a special flag, -p which specifies the interpreter
+        that should be used to run the script (the default is /bin/sh).
+        Sometimes the -p option is used with no body in order to run a single
+        command directly rather than having to spawn a shell to invoke the
+        programs (i.e. %post -p /sbin/ldconfig).  Note that this form requires
+        that there be nothing but white space (not even comments) until the
+        next section begins.
+      </para>
+
+      <para>
         Cross Reference
       </para>
       <para>