+UNAME=$(shell uname)
+UNAME_A=$(shell uname -a)
+DARWIN_LIBC=$(shell file /usr/lib/libc.dylib)
+
+OS_AIX=$(shell expr "$(UNAME)" : '.*AIX.*')
+OS_SUNOS=$(shell expr "$(UNAME)" : '.*SunOS.*')
+OS_DARWIN=$(shell expr "$(UNAME)" : '.*Darwin.*')
+ifneq ($(OS_DARWIN),0)
+ OS_DARWIN64=$(shell expr "$(DARWIN_LIBC)" : '.*x86_64.*')
+else
+ OS_DARWIN64=0
+endif
+OS_CYGWIN=$(shell expr "$(UNAME)" : '.*CYGWIN.*')
+OS_LINUX=$(shell expr "$(UNAME)" : '.*Linux.*')
+OS_LINUX64=$(shell expr "$(UNAME_A)" : '.*Linux.*x86_64.*')
+