gnu: Add dash.

* gnu/packages/shells.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Register it.

gnu/local.mk

@@ -310,6 +310,7 @@ GNU_SYSTEM_MODULES =				\
   %D%/packages/search.scm			\
   %D%/packages/serialization.scm		\
   %D%/packages/serveez.scm			\
+  %D%/packages/shells.scm			\
   %D%/packages/shellutils.scm			\
   %D%/packages/shishi.scm			\
   %D%/packages/skarnet.scm			\

gnu/packages/shells.scm

@@ -0,0 +1,60 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2016 Tobias Geerinckx-Rice <me@tobias.gr>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix 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.
+;;;
+;;; GNU Guix 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 GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (gnu packages shells)
+  #:use-module (gnu packages libedit)
+  #:use-module (guix build-system gnu)
+  #:use-module (guix download)
+  #:use-module (guix licenses)
+  #:use-module (guix packages))
+
+(define-public dash
+  (package
+    (name "dash")
+    (version "0.5.9")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (string-append "http://gondor.apana.org.au/~herbert/dash/files/"
+                           name "-" version ".tar.gz"))
+       (sha256
+        (base32
+         "17328wd9n5krr5wd37smrk0y7fdf8aa3hmhm02br5mqpq0a3nycj"))
+       (modules '((guix build utils)))
+       (snippet
+        '(begin
+           ;; The man page hails from BSD, where (d)ash is the default shell.
+           ;; This isn't the case on Guix or indeed most other GNU systems.
+           (substitute* "src/dash.1"
+             (("the standard command interpreter for the system")
+              "a command interpreter based on the original Bourne shell"))
+           #t))))
+    (build-system gnu-build-system)
+    (inputs
+     `(("libedit" ,libedit)))
+    (arguments
+     `(#:configure-flags '("--with-libedit")))
+    (home-page "http://gondor.apana.org.au/~herbert/dash")
+    (synopsis "POSIX-compliant shell optimised for size")
+    (description
+     "dash is a POSIX-compliant @command{/bin/sh} implementation that aims to be
+as small as possible, often without sacrificing speed.  It is faster than the
+GNU Bourne-Again Shell (@command{bash}) at most scripted tasks.  dash is a
+direct descendant of NetBSD's Almquist Shell (@command{ash}).")
+    (license (list bsd-3
+                   gpl2+))))    ; mksignames.c