DOC_MAN1=$(patsubst %.txt,%.1,$(MAN1_TXT))
DOC_MAN7=$(patsubst %.txt,%.7,$(MAN7_TXT))
-prefix=$(HOME)
+prefix?=$(HOME)
bin=$(prefix)/bin
mandir=$(prefix)/man
man1=$(mandir)/man1
man7=$(mandir)/man7
# DESTDIR=
-INSTALL=install
+INSTALL?=install
#
# Please note that there is a minor bug in asciidoc.