diff --git a/ChangeLog b/ChangeLog
index 9cdcb28ae0..adf4b5a93c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+Mon Jan 20 21:48:43 2003  Akinori MUSHA  <knu@iDaemons.org>
+
+	* configure.in (MANTYPE): Detect if the system's nroff(1) groks
+	  mdoc.  Provide a new option --with-mantype={doc|man} in case the
+	  check does not work as expected.
+
+	* Makefile.in (MANTYPE): Define MANTYPE and pass it to
+	  instruby.rb.
+
+	* instruby.rb: Convert mdoc manpages to man for systems which
+	  nroff(1) does not grok mdoc.
+
 Mon Jan 20 21:25:18 2003  Akinori MUSHA  <knu@iDaemons.org>
 
 	* lib/tempfile.rb (self.open): If a block is given, call it with
diff --git a/Makefile.in b/Makefile.in
index df6d52bc17..c4a229cf15 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -100,6 +100,8 @@ OBJS	      = array.@OBJEXT@ \
 		version.@OBJEXT@ \
 		$(MISSING)
 
+MANTYPE	      = @MANTYPE@
+
 all:		@MAKEFILES@ miniruby$(EXEEXT) rbconfig.rb $(LIBRUBY)
 		@$(MINIRUBY) $(srcdir)/ext/extmk.rb --extstatic="@EXTSTATIC@" --make="$(MAKE)" --make-flags="$(MFLAGS)$(MAKEFLAGS)"
 
@@ -126,11 +128,11 @@ ruby.imp:	$(LIBRUBY_A)
 # $(MINIRUBY) $< $@
 
 install:	rbconfig.rb
-		$(MINIRUBY) $(srcdir)/instruby.rb --make="$(MAKE)" --make-flags="$(MFLAGS)$(MAKEFLAGS)" $(DESTDIR)
+		$(MINIRUBY) $(srcdir)/instruby.rb --make="$(MAKE)" --make-flags="$(MFLAGS)$(MAKEFLAGS)" --mantype=$(MANTYPE) $(DESTDIR)
 		$(MINIRUBY) $(srcdir)/ext/extmk.rb --make="$(MAKE)" --make-flags="$(MFLAGS)$(MAKEFLAGS) DESTDIR=$(DESTDIR)" install
 
 what-where no-install:	rbconfig.rb
-		$(MINIRUBY) $(srcdir)/instruby.rb --make="$(MAKE)" --make-flags="$(MFLAGS)$(MAKEFLAGS) -n" $(DESTDIR)
+		$(MINIRUBY) $(srcdir)/instruby.rb --make="$(MAKE)" --make-flags="$(MFLAGS)$(MAKEFLAGS) -n" --mantype=$(MANTYPE) $(DESTDIR)
 		$(MINIRUBY) $(srcdir)/ext/extmk.rb --make="$(MAKE)" --make-flags="$(MFLAGS)$(MAKEFLAGS) -n DESTDIR=$(DESTDIR)" install
 
 clean-ext:
diff --git a/configure.in b/configure.in
index da620ec081..0ea68cca99 100644
--- a/configure.in
+++ b/configure.in
@@ -1304,6 +1304,28 @@ if test "$search_path" != ""; then
     AC_DEFINE_UNQUOTED(RUBY_SEARCH_PATH,"$search_path")
 fi
 
+AC_ARG_WITH(mantype,
+		[  --with-mantype=TYPE specify man page type; TYPE is one of man and doc],
+		[
+			case "$withval" in
+			man|doc)
+				MANTYPE=$withval
+				;;
+			*)
+				AC_MSG_ERROR(invalid man type: $withval)
+				;;
+			esac
+		])
+if test -z "$MANTYPE"; then
+	AC_PATH_PROGS(NROFF, nroff awf, /bin/false, "/usr/bin:/usr/ucb")
+	if ${NROFF} -mdoc ${srcdir}/ruby.1 >/dev/null 2>&1; then
+		MANTYPE=doc
+	else
+		MANTYPE=man
+	fi
+fi
+AC_SUBST(MANTYPE)
+
 if test -f config.h && tr -d '\015' < confdefs.h | cmp -s config.h -; then
   echo "config.h unchanged"
 else
diff --git a/instruby.rb b/instruby.rb
index c05ef2076c..89390f949a 100644
--- a/instruby.rb
+++ b/instruby.rb
@@ -7,10 +7,11 @@ $:.unshift File.join(CONFIG["srcdir"], "lib")
 require 'fileutils'
 require 'shellwords'
 require 'getopts'
+require 'tempfile'
 
 File.umask(0)
 
-getopts("n", "make:", "make-flags:")
+getopts("n", "make:", "make-flags:", "mantype:doc")
 $dryrun = $OPT["n"]
 mflags = Shellwords.shellwords($OPT["make-flags"] || "").uniq
 mflags[0].sub!(/^\w+$/, '-\&') unless mflags.empty?
@@ -18,6 +19,7 @@ make, *mflags[0, 0] = Shellwords.shellwords($OPT['make'] || ENV["MAKE"] || "")
 mflags = mflags.grep(/^-([^-])/){$1}.join
 mflags.downcase! if /nmake/i == make
 $dryrun = true if mflags.include?(?n)
+mantype = $OPT["mantype"]
 
 ARGV.delete_if{|x|x[0] == ?-}
 destdir = ARGV[0] || ''
@@ -40,14 +42,14 @@ rubylibdir = destdir+CONFIG["rubylibdir"]
 archlibdir = destdir+CONFIG["archdir"]
 sitelibdir = destdir+CONFIG["sitelibdir"]
 sitearchlibdir = destdir+CONFIG["sitearchdir"]
-mandir = File.join(destdir+CONFIG["mandir"], "man1")
+mandir = File.join(destdir+CONFIG["mandir"], "man")
 configure_args = Shellwords.shellwords(CONFIG["configure_args"])
 enable_shared = CONFIG["ENABLE_SHARED"] == 'yes'
 dll = CONFIG["LIBRUBY_SO"]
 lib = CONFIG["LIBRUBY"]
 arc = CONFIG["LIBRUBY_A"]
 
-makedirs [bindir, libdir, rubylibdir, archlibdir, sitelibdir, sitearchlibdir, mandir]
+makedirs [bindir, libdir, rubylibdir, archlibdir, sitelibdir, sitearchlibdir]
 
 install ruby_install_name+exeext, File.join(bindir, ruby_install_name+exeext), 0755
 if rubyw_install_name and !rubyw_install_name.empty?
@@ -115,14 +117,38 @@ Dir.glob("lib/**/*{.rb,help-message}") do |f|
   install f, dir, 0644
 end
 
-for f in Dir["*.h"]
+Dir.glob("*.h") do |f|
   install f, archlibdir, 0644
 end
+
 if RUBY_PLATFORM =~ /mswin32|mingw|bccwin32/
   makedirs File.join(archlibdir, "win32")
   install "win32/win32.h", File.join(archlibdir, "win32"), 0644
 end
 
-install "ruby.1", File.join(mandir, ruby_install_name+".1"), 0644
+Dir.glob("*.[1-9]") do |mdoc|
+  section = mdoc[-1,1]
+
+  destdir = mandir + section
+  destfile = File.join(destdir, mdoc.sub(/ruby/, ruby_install_name))
+
+  makedirs destdir
+
+  if mantype == "doc"
+    install mdoc, destfile, 0644
+  else
+    require 'mdoc2man.rb'
+
+    w = Tempfile.open(mdoc)
+
+    open(mdoc) { |r|
+      Mdoc2Man.mdoc2man(r, w)
+    }
+
+    w.close
+
+    install w.path, destfile, 0644
+  end
+end
 
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