Add the 'read' utility

* geesh/built-ins/read.scm: New file.
* Makefile.am: Add it.
* geesh/built-ins.scm (*built-ins*): Define 'read'.

Makefile.am

@@ -38,6 +38,7 @@ test-list: ; @echo $(TESTS)
 
 MODULES =                                       \
   geesh/built-ins/echo.scm                      \
+  geesh/built-ins/read.scm                      \
   geesh/built-ins.scm                           \
   geesh/environment.scm                         \
   geesh/eval.scm                                \

geesh/built-ins.scm

@@ -65,7 +65,7 @@
     ("kill" . ,undefined)
     ("newgrp" . ,undefined)
     ("pwd" . ,undefined)
-    ("read" . ,undefined)
+    ("read" . ,(@@ (geesh built-ins read) main))
     ("true" . ,undefined)
     ("umask" . ,undefined)
     ("unalias" . ,undefined)

geesh/built-ins/read.scm

@@ -0,0 +1,31 @@
+;;; The Geesh Shell Interpreter
+;;; Copyright 2018 Timothy Sample <samplet@ngyro.com>
+;;;
+;;; This file is part of Geesh.
+;;;
+;;; Geesh 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.
+;;;
+;;; Geesh 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 Geesh.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (geesh built-ins read)
+  #:use-module (geesh environment)
+  #:use-module (ice-9 rdelim))
+
+;;; Commentary:
+;;;
+;;; The 'read' utility.
+;;;
+;;; Code:
+
+(define (main env . args)
+  (set-var! env (car args) (read-line (current-input-port)))
+  0)