UNIX98 requires unistd.h for getopt, and requires -D_XOPEN_SOURCE=500.

@@ -23,11 +23,11 @@
 # Makefile for "ifparse" 
 #
 # Copyright 2000-2003 Sun Microsystems, Inc.  All rights reserved.
 # Use is subject to license terms.
 #
-# ident "%Z%%M% %I%     %E% SMI"
+# Copyright 2014 Garrett D'Amore <garrett@damore.org>
 #
 
 PROG =          ifparse
 ROOTFS_PROG =   $(PROG)
 OBJS=           ifparse.o

@@ -38,12 +38,12 @@
 
 CPPFLAGS += -I$(CMDINETCOMMONDIR)
 LINTFLAGS +=    -m
 
 # these #defines are required to use UNIX 98 interfaces
-$(OBJS)         := CPPFLAGS +=-D_POSIX_C_SOURCE 
-LINTFLAGS       += -D_POSIX_C_SOURCE -I$(CMDINETCOMMONDIR)
+$(OBJS)         := CPPFLAGS +=-D_XOPEN_SOURCE=500       
+LINTFLAGS       += -D_XOPEN_SOURCE=500 -I$(CMDINETCOMMONDIR)
 
 .KEEP_STATE:
 
 all:    $(ROOTFS_PROG)