--- mk.config.orig	Sat Dec  3 23:24:49 2005
+++ mk.config	Sat Dec  3 23:26:07 2005
@@ -1,57 +1,57 @@
 #
 # A BSD-compatible install command.
 #
-INSTALL=/usr/ucb/install
+INSTALL?=/usr/ucb/install
 
 #
 # Where to place the troff macro packages.
 #
-MACDIR=/usr/ucblib/doctools/tmac
+MACDIR?=/usr/ucblib/doctools/tmac
 
 #
 # Where to place the troff font files.
 #
-FNTDIR=/usr/ucblib/doctools/font
+FNTDIR?=/usr/ucblib/doctools/font
 
 #
 # Where to place PostScript helper files.
 #
-PSTDIR=$(FNTDIR)/devpost/postscript
+PSTDIR?=$(FNTDIR)/devpost/postscript
 
 #
 # Where to place the nroff terminal description files.
 #
-TABDIR=/usr/ucblib/doctools/nterm
+TABDIR?=/usr/ucblib/doctools/nterm
 
 #
 # Where to place troff hyphenation files.
 #
-HYPDIR=/usr/ucblib/doctools/hyphen
+HYPDIR?=/usr/ucblib/doctools/hyphen
 
 #
 # Where to place files belonging to the "refer" utility.
 #
-REFDIR=/usr/ucblib/reftools
+REFDIR?=/usr/ucblib/reftools
 
 #
 # Where to place ASCII charts and the like.
 #
-PUBDIR=/usr/pub
+PUBDIR?=/usr/pub
 
 #
 # Where to place binaries.
 #
-BINDIR=/usr/ucb
+BINDIR?=/usr/ucb
 
 #
 # Where to place libraries.
 #
-LIBDIR=/usr/ucblib
+LIBDIR?=/usr/ucblib
 
 #
 # Where to place manual pages.
 #
-MANDIR=/usr/share/man/5man
+MANDIR?=/usr/share/man/5man
 
 #
 # Define this if you want troff and nroff to be able to process
@@ -68,7 +68,7 @@
 #
 # The C compiler.
 #
-CC=cc
+CC?=cc
 
 #
 # The C++ compiler.
@@ -78,7 +78,7 @@
 #
 # Compiler flags.
 #
-CFLAGS=-O
+CFLAGS?=-O
 
 #
 # C preprocessor flags.
@@ -86,13 +86,13 @@
 # Use -D_GNU_SOURCE for Linux with GNU libc.
 # Use -D_INCLUDE__STDC_A1_SOURCE for HP-UX.
 #
-CPPFLAGS=-D_GNU_SOURCE
+CPPFLAGS?=-D_GNU_SOURCE
 
 #
 # Warning flags for the compiler.
 #
-WERROR=-Werror
-WARN = -Wchar-subscripts -Wformat -Wno-format-y2k -Wimplicit \
+WERROR?=-Werror
+WARN?= -Wchar-subscripts -Wformat -Wno-format-y2k -Wimplicit \
 	-Wmissing-braces -Wsequence-point -Wreturn-type -Wtrigraphs \
 	-Wunused-function -Wunused-label -Wunused-variable -Wunused-value \
 	-Wuninitialized -Wmultichar -Wpointer-arith -Wno-missing-braces \
@@ -102,9 +102,9 @@
 #
 # Linker flags.
 #
-LDFLAGS=
+LDFLAGS?=
 
 #
 # Additional libraries to link with.
 #
-LIBS=
+LIBS?=