Add update script

diff --git a/update b/update
new file mode 100755 (executable)
index 0000000..552c1e5
--- /dev/null
+++ b/update
@@ -0,0 +1,23 @@
+#! /bin/sh
+
+current="`git config --get --path remote.current.url`"
+origin="`git config --get --path remote.origin.url`"
+
+if [ -n "$origin" ]; then
+   if [ -n "$current" ]; then
+      echo "UNKNOWN ERROR"
+   else
+      echo "This script must be run in the origin directory: $origin"
+   fi >&2
+   exit 1
+elif [ -z "$current" ]; then
+   echo "UNKNOWN ERROR" >&2
+   exit 1
+fi
+
+git pull --ff-only current master &&
+
+web="`git config --get --path remote.web.url`" &&
+[ -n "$web" ] && git push web
+
+cd "$current" && exec git pull origin