--- Makefile.orig	2026-09-05 12:24:46 UTC
+++ Makefile
@@ -15,21 +15,21 @@ TARFILE_NAME	=	nifticlib-2.0.0
 
 
 ## Compiler  defines
-cc		=	gcc
-CC		=	gcc
-AR		=	ar
-RANLIB  = ranlib
+cc		?=	gcc
+CC		?=	gcc
+AR		?=	ar
+RANLIB  	?=	ranlib
 DEPENDFLAGS	=	-MM
 GNU_ANSI_FLAGS	= 	-Wall -ansi -pedantic
 ANSI_FLAGS	= 	${GNU_ANSI_FLAGS}
-CFLAGS		=	$(ANSI_FLAGS)
+CFLAGS		+=	$(ANSI_FLAGS)
 
 ## Command defines
 ## gmake does not work on MacOSX or some versions of linux MAKE  = gmake
-RM		=	rm
-MV		=	mv
-CP		=	cp
-TAR		=	/usr/local/pkg/gnu/bin/tar
+RM		?=	rm
+MV		?=	mv
+CP		?=	cp
+TAR		?=	/usr/local/pkg/gnu/bin/tar
 
 
 ## Installation
@@ -39,9 +39,9 @@ INSTALL_INC_DIR	=	include
 
 
 ## Zlib defines
-ZLIB_INC	=	-I/usr/include
-ZLIB_PATH	=	-L/usr/lib
-ZLIB_LIBS 	= 	$(ZLIB_PATH) -lm -lz
+ZLIB_INC	?=	-I/usr/include
+ZLIB_PATH	?=	-L/usr/lib
+ZLIB_LIBS 	?= 	$(ZLIB_PATH) -lm -lz
 
 ##############################################################
 # platform specific redefines (to use, set ARCH appropriately)
@@ -71,24 +71,24 @@ endif
 #################################################################
 
 ## ZNZ defines
-ZNZ_INC		=	-I../$(ZNZ)
-ZNZ_PATH	=	-L../$(ZNZ)
-ZNZ_LIBS	=	$(ZNZ_PATH)  -lznz
+ZNZ_INC		?=	-I../$(ZNZ)
+ZNZ_PATH	?=	-L../$(ZNZ)
+ZNZ_LIBS	?=	$(ZNZ_PATH)  -lznz
 USEZLIB         =       -DHAVE_ZLIB
 
 ## NIFTI defines
-NIFTI_INC	=	-I../$(NIFTI)
-NIFTI_PATH	=	-L../$(NIFTI)
+NIFTI_INC	?=	-I../$(NIFTI)
+NIFTI_PATH	?=	-L../$(NIFTI)
 NIFTI_LIBS	=	$(NIFTI_PATH) -lniftiio
 
 ## NIFTICDF defines
-NIFTICDF_INC	=	-I../$(NIFTICDF)
-NIFTICDF_PATH	=	-L../$(NIFTICDF)
+NIFTICDF_INC	?=	-I../$(NIFTICDF)
+NIFTICDF_PATH	?=	-L../$(NIFTICDF)
 NIFTICDF_LIBS	=	$(NIFTICDF_PATH) -lnifticdf
 
 ## FSLIO defines
-FSLIO_INC	=	-I../$(FSLIO)
-FSLIO_PATH	=	-L../$(FSLIO)
+FSLIO_INC	?=	-I../$(FSLIO)
+FSLIO_PATH	?=	-L../$(FSLIO)
 FSLIO_LIBS	=	$(FSLIO_PATH) -lfslio