Add (ice-9 textual-ports)

* module/ice-9/textual-ports.scm: New module.
* module/Makefile.am: Add new module.

module/Makefile.am

@@ -111,6 +111,7 @@ SOURCES =					\
   ice-9/streams.scm				\
   ice-9/string-fun.scm				\
   ice-9/syncase.scm				\
+  ice-9/textual-ports.scm			\
   ice-9/threads.scm				\
   ice-9/time.scm				\
   ice-9/top-repl.scm				\

module/ice-9/textual-ports.scm

@@ -0,0 +1,57 @@
+;;;; textual-ports.scm --- Textual I/O on ports
+
+;;;;	Copyright (C) 2016 Free Software Foundation, Inc.
+;;;;
+;;;; This library is free software; you can redistribute it and/or
+;;;; modify it under the terms of the GNU Lesser General Public
+;;;; License as published by the Free Software Foundation; either
+;;;; version 3 of the License, or (at your option) any later version.
+;;;;
+;;;; This library 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
+;;;; Lesser General Public License for more details.
+;;;;
+;;;; You should have received a copy of the GNU Lesser General Public
+;;;; License along with this library; if not, write to the Free Software
+;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+;;; Commentary:
+;;;
+;;; Code:
+
+(define-module (ice-9 textual-ports)
+  #:use-module (ice-9 ports internal)
+  #:use-module (ice-9 binary-ports)
+  #:use-module (ice-9 rdelim)
+  #:re-export (get-string-n!
+               put-char
+               put-string)
+  #:export (get-char
+            lookahead-char
+            get-string-n
+            get-string-all
+            get-line))
+
+(define (get-char port)
+  (read-char port))
+
+(define (lookahead-char port)
+  (peek-char port))
+
+(define (get-line port)
+  (read-line port 'trim))
+
+(define (get-string-all port)
+  (read-string port))
+
+(define (get-string-n port count)
+  "Read up to @var{count} characters from @var{port}.
+If no characters could be read before encountering the end of file,
+return the end-of-file object, otherwise return a string containing
+the characters read."
+  (let* ((s (make-string count))
+         (rv (get-string-n! port s 0 count)))
+    (cond ((eof-object? rv) rv)
+          ((= rv count)     s)
+          (else             (substring/shared s 0 rv)))))