diff --git a/docs/ekg2book-en/develbook.xml b/docs/ekg2book-en/develbook.xml
index 5be2dfb15..fe872dc08 100644
--- a/docs/ekg2book-en/develbook.xml
+++ b/docs/ekg2book-en/develbook.xml
@@ -365,9 +365,9 @@ Copyright 2000 Free Software Foundation, Inc.
          </para>
          <programlisting role="shell">
 <![CDATA[
-grep -R -I 'format_add("' * | cut -d: -f2- | \
-   perl -ne '/format_add\("(.*?)".+"(.*)".*/; print $1." ".$2."\n"' \
-   > my.theme
+find . -name '*.c' -type f | xargs sed \
+    '/^[ \t]*format_add("/!d;s///;s/"[^"]*"\(.*\)".*/ \1/' \
+    > my.theme
    ]]>
          </programlisting>
          <para>
diff --git a/docs/ekg2book/develbook.xml b/docs/ekg2book/develbook.xml
index f96b50d33..8f061ae71 100644
--- a/docs/ekg2book/develbook.xml
+++ b/docs/ekg2book/develbook.xml
@@ -363,9 +363,9 @@ Copyright 2000 Free Software Foundation, Inc.
          </para>
          <programlisting role="shell">
 <![CDATA[
-grep -R -I 'format_add("' * | cut -d: -f2- | \
-   perl -ne '/format_add\("(.*?)".+"(.*)".*/; print $1." ".$2."\n"' \
-   > my.theme
+find . -name '*.c' -type f | xargs sed \
+    '/^[ \t]*format_add("/!d;s///;s/"[^"]*"\(.*\)".*/ \1/' \
+    > my.theme
    ]]>
          </programlisting>
          <para>