+bisonver=`bison --version`
+
+if [ "$bisonver" = "" ]; then
+ echo Bison is needed to compile Claws Mail CVS
+ exit 1
+fi
+
+flexver=`flex --version|sed "s/.* //"`
+
+if [ "$flexver" = "" ]; then
+ echo Flex 2.5.31 or greater is needed to compile Claws Mail CVS
+ exit 1
+else
+ flex_major=`echo $flexver|sed "s/\..*//"`
+ flex_minor=`echo $flexver|sed "s/$flex_major\.\(.*\)\..*/\1/"`
+ flex_micro=`echo $flexver|sed "s/$flex_major\.$flex_minor\.\(.*\)/\1/"`
+ if [ $flex_major -lt 2 -o $flex_minor -lt 5 -o $flex_micro -lt 31 ]; then
+ echo Flex 2.5.31 or greater is needed to compile Claws Mail CVS
+ exit 1
+ fi
+fi
+