cuirass: Add command line options.

* bin/cuirass.in (show-help, %options): new variables.
(main): Adapt.
* src/cuirass/ui.scm: New file.
* Makefile.am (dist_pkgmodule_DATA): Add it.

Makefile.am

@@ -3,7 +3,10 @@
 bin_SCRIPTS = bin/cuirass
 noinst_SCRIPTS = pre-inst-env
 
-dist_pkgmodule_DATA = src/cuirass/base.scm
+dist_pkgmodule_DATA = \
+  src/cuirass/base.scm \
+  src/cuirass/ui.scm
+
 nodist_pkgmodule_DATA = \
   $(dist_pkgmodule_DATA:%.scm=%.go) \
   src/cuirass/config.scm \

bin/cuirass.in

@@ -22,8 +22,26 @@ exec ${GUILE:-@GUILE@} --no-auto-compile -e main -s "$0" "$@"
 ;;; along with Cuirass.  If not, see <http://www.gnu.org/licenses/>.
 
 (use-modules (cuirass base)
+             (cuirass ui)
+             (ice-9 getopt-long)
              (ice-9 match))
 
+(define* (show-help #:optional (prog (program-name)))
+  (simple-format #t "Usage: ~a [OPTIONS] [CACHEDIR]" prog)
+  (display "
+Run Guix job from a git repository cloned in CACHEDIR.
+
+  -I, --interval[=]N        Wait N seconds between each evaluation
+  -V, --version             Display version
+  -h, --help                Display this help message")
+  (newline)
+  (show-package-information))
+
+(define %options
+  `((interval (single-char #\I) (value #t))
+    (version  (single-char #\V) (value #f))
+    (help     (single-char #\h) (value #f))))
+
 (define %guix-repository
   (make-parameter "git://git.savannah.gnu.org/guix.git"))
 
@@ -92,12 +110,22 @@ DIR if required."
 ;;;
 
 (define* (main #:optional (args (command-line)))
-  (match args
-    ((program interval)
-     (let ((cachedir (getenv "CUIRASS_CACHEDIR")))
-       (while #t
-         (pull-changes cachedir)
-         (compile cachedir)
-         (evaluate cachedir)
-         (sleep (string->number interval)))))
-    (_ (main (list (car args) "60")))))
+  (let ((opts     (getopt-long args %options))
+        (progname "cuirass"))
+    (cond
+     ((option-ref opts 'help #f)
+      (show-help progname)
+      (exit 0))
+     ((option-ref opts 'version #f)
+      (show-version progname)
+      (exit 0))
+     (else
+      (let* ((args     (option-ref opts '() #f))
+             (cachedir (if (null? args)
+                           (getenv "CUIRASS_CACHEDIR")
+                           (car args))))
+        (while #t
+          (pull-changes cachedir)
+          (compile cachedir)
+          (evaluate cachedir)
+          (sleep (string->number (option-ref opts 'interval "60")))))))))

src/cuirass/ui.scm

@@ -0,0 +1,39 @@
+;;;; ui.scm - user interface facilities for command-line tools
+;;;
+;;; Copyright © 2016 Mathieu Lirzin <mthl@gnu.org>
+;;;
+;;; This file is part of Cuirass.
+;;;
+;;; Cuirass 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.
+;;;
+;;; Cuirass 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 Cuirass.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (cuirass ui)
+  #:use-module (cuirass config)
+  #:export (show-version
+            show-package-information))
+
+(define (show-version prog)
+  "Display version information for COMMAND."
+  (simple-format #t "~a (~a) ~a~%" prog %package-name %package-version)
+  (display "Copyright (C) 2016 the Cuirass authors
+License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
+This is free software: you are free to change and redistribute it.
+There is NO WARRANTY, to the extent permitted by law.")
+  (newline))
+
+(define (show-package-information)
+  (newline)
+  (format #t "Report bugs to: ~a." %package-bugreport)
+  (newline)
+  (display "General help using GNU software: <http://www.gnu.org/gethelp/>")
+  (newline))