ui: Add 'build' subcommand.

* haunt/ui/build.scm: New file.
* Makefile.am (SOURCES): Add it.

Makefile.am

@@ -48,6 +48,7 @@ SOURCES =					\
   haunt/site.scm				\
   haunt/build/html.scm				\
   haunt/ui.scm					\
+  haunt/ui/build.scm				\
   haunt/ui/serve.scm				\
   haunt/serve/mime-types.scm			\
   haunt/serve/web-server.scm

haunt/ui/build.scm

@@ -0,0 +1,61 @@
+;;; Haunt --- Static site generator for GNU Guile
+;;; Copyright © 2015 David Thompson <davet@gnu.org>
+;;;
+;;; This file is part of Haunt.
+;;;
+;;; Haunt is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or
+;;; (at your option) any later version.
+;;;
+;;; Haunt is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;;; General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with Haunt.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+;;
+;; Haunt build sub-command.
+;;
+;;; Code:
+
+(define-module (haunt ui build)
+  #:use-module (srfi srfi-37)
+  #:use-module (ice-9 match)
+  #:use-module (haunt site)
+  #:use-module (haunt config)
+  #:use-module (haunt ui)
+  #:export (haunt-build))
+
+(define (show-help)
+  (format #t "Usage: haunt build [OPTION]
+Compile the site defined in the current directory.~%")
+  (show-common-options-help)
+  (newline)
+  (display "
+  -h, --help             display this help and exit")
+  (display "
+  --version              display version information and exit")
+  (newline))
+
+(define %options
+  (cons* (option '(#\h "help") #f #f
+                 (lambda _
+                   (show-help)
+                   (exit 0)))
+         (option '(#\V "version") #f #f
+                 (lambda _
+                   (show-version-and-exit "haunt build")))
+         %common-options))
+
+(define %default-options %default-common-options)
+
+(define (haunt-build . args)
+  (let* ((opts (simple-args-fold args %options %default-options))
+         (site (load-config (assq-ref opts 'config))))
+    (format #t "building pages in '~a'...~%" (site-build-directory site))
+    (build-site site)
+    (display "build completed successfully\n")))