autogen.sh: advice about installing libtool

libtool not being present in a system meant that this cryptic
error about LT_INIT would be shown:

sources/glue/Makefile.am:1: error: Libtool library used but 'LIBTOOL' is undefined
sources/glue/Makefile.am:1:   The usual way to define 'LIBTOOL' is to add 'LT_INIT'
sources/glue/Makefile.am:1:   to 'configure.ac' and run 'aclocal' and 'autoconf' again.
sources/glue/Makefile.am:1:   If 'LT_INIT' is in 'configure.ac', make sure
sources/glue/Makefile.am:1:   its definition is in aclocal's search path.
autoreconf: automake failed with exit status: 1

diff --git a/autogen.sh b/autogen.sh
index c012414..55fba17 100755 (executable)
--- a/autogen.sh
+++ b/autogen.sh
@@ -3,6 +3,11 @@ which autoreconf > /dev/null
 if [ $? -ne 0 ] ; then
        echo "Please install autoconf" && exit 1;
 fi
+which libtool > /dev/null 2>&1
+if [ $? -ne 0 ] ; then
+       echo "Please install libtool" && exit 1;
+fi
+
 mkdir -p m4
 autoreconf  -i --force --warnings=none -I . -I m4 && \
 ./configure --enable-maintainer-mode $*