set GLUON_BRANCH via option and add print_usage()

build.sh

@@ -1,23 +1,78 @@
 #!/bin/bash
+# (pushd/popd needs an advanced shell)
 
 set -e
 
 SCRIPTDIR=$(dirname $0)
 
+print_usage() {
+    echo "Usage: $0 [GLUON_BRANCH]"
+    echo ''
+    echo 'If GLUON_BRANCH is not given, experimental is set.'
+    echo ''
+    echo 'Options:'
+    echo '  -h  show this help'
+}
+
+# command line options handling
+ARGS=`getopt h $*`
+if [ $? -ne 0 ]
+then
+    print_usage
+    exit 2
+fi
+set -- $ARGS
+
+while true
+do
+    case "$1" in
+        -h)
+            print_usage
+            exit 0
+            ;;
+        --)
+            shift; break;;
+    esac
+done
+
+# set GLUON_BRANCH for manifest
+if [ -z "$1" ]
+then
+    GLUON_BRANCH=experimental
+    echo 'Set GLUON_BRANCH to "experimental"!'
+else
+    GLUON_BRANCH=$1
+fi
+
+case "xx$GLUON_BRANCH" in
+    'xxstable'|'xxbeta'|'xxexperimental')
+        # fine
+        ;;
+    *)
+        echo "Unknown GLUON_BRANCH '$1'."
+        echo 'Use "stable", "beta", or "experimental"!'
+        exit 1
+        ;;
+esac
+
+# get GLUON_CHECKOUT from site dir
 pushd ${SCRIPTDIR}
 eval `make -s -f helper.mk`
 echo "GLUON_CHECKOUT: ${GLUON_CHECKOUT}"
 
+# build
 pushd ..
 git checkout master
 git pull
 git checkout ${GLUON_CHECKOUT}
 make clean
 make update
 make all -j4
-make manifest
+GLUON_BRANCH=${GLUON_BRANCH} make manifest
 popd
 
 popd
 
 exit 0
+
+# vim: set et sts=0 ts=4 sw=4 sr: