install -D not supported on mac

Makefile

@@ -20,8 +20,13 @@ TARGET = pcapmirror
 
 # Installation directory
 PREFIX = /usr
-ifdef prefix
+
-PREFIX = $(prefix)
+ifndef BINDIR
+BINDIR = $(DESTDIR)$(PREFIX)/bin
+endif
+
+ifndef MANDIR
+MANDIR = $(DESTDIR)$(PREFIX)/share/man
 endif
 
 # Default rule
@@ -48,8 +53,8 @@ clean:
 # Install the executable
 install: $(TARGET)
 		mkdir -p $(DESTDIR)$(PREFIX)/bin
-		install -s -D $(TARGET) $(DESTDIR)$(PREFIX)/bin/$(TARGET)
+		install -s $(TARGET) $(BINDIR)/$(TARGET)
-		install -D $(TARGET).8 $(DESTDIR)$(PREFIX)/share/man/man8/$(TARGET).8
+		install $(TARGET).8 $(MANDIR)/man8/$(TARGET).8
 		
 
 # Uninstall the executable