+DEBIAN=$(shell expr "`cat /etc/issue 2> /dev/null`" : '.*Debian.*')
+UBUNTU=$(shell expr "`cat /etc/issue 2> /dev/null`" : '.*Ubuntu.*')
+SUSE=$(shell expr "`cat /etc/issue 2> /dev/null`" : '.*SuSE.*')
+SUSE91=$(shell expr "`cat /etc/issue 2> /dev/null`" : '.*SuSE Linux 9.1.*')
+REDHAT=$(shell expr "`cat /etc/issue 2> /dev/null`" : '.*Red Hat.*')
+MANDRAKE=$(shell expr "`cat /etc/issue 2> /dev/null`" : '.*Mandrake.*')
+DARWIN=$(shell expr "`uname -a`" : '.*Darwin.*')
+
+ifneq (${DEBIAN},0)
+OS:=debian
+else
+ ifneq (${SUSE91},0)
+ OS=suse91
+ else
+ ifneq (${SUSE},0)
+ OS=suse
+ else
+ ifneq (${REDHAT},0)
+ OS=redhat
+ else
+ ifneq (${MANDRAKE},0)
+ OS=mandrake
+ else
+ ifneq (${DARWIN},0)
+ OS=darwin
+ else
+ ifneq (${UBUNTU},0)
+ OS=ubuntu
+ endif
+ endif
+ endif
+ endif
+ endif
+ endif
+endif
+