+# Prints the current OS. Supported are Debian (debian), Gentoo (gentoo) and
+# Mac OS X (darwin) at the moment. If an unsupported OS is used an error is
+# printed.
+os() {
+ if [ -f /etc/debian_version ]; then
+ echo debian
+ elif [ -f /etc/gentoo-release ]; then
+ echo gentoo
+ elif [ x`uname` = xDarwin ]; then
+ echo darwin
+ else
+ echo unsupported OS! >&2
+ return 1
+ fi
+}
+