From c5e098bc35d001cbf920bd9586ba21a23acbf90a Mon Sep 17 00:00:00 2001
From: Jan Nieuwenhuizen <janneke@gnu.org>
Date: Sat, 2 Mar 2019 22:27:39 +0100
Subject: [PATCH] mescc: Mes C Library: Fix isatty.

* lib/posix/isatty.c (isatty): Test ioctl == 0.
* mes/module/mes/boot-0.scm.in: Update: no tty?: read from stdin.
---
 lib/posix/isatty.c           | 56 +++++++++++++++++++++++++++++++++---
 mes/module/mes/boot-0.scm.in |  2 +-
 2 files changed, 53 insertions(+), 5 deletions(-)

diff --git a/lib/posix/isatty.c b/lib/posix/isatty.c
index 6ee18077..41353146 100644
--- a/lib/posix/isatty.c
+++ b/lib/posix/isatty.c
@@ -1,6 +1,6 @@
 /* -*-comment-start: "//";comment-end:""-*-
  * GNU Mes --- Maxwell Equations of Software
- * Copyright © 2016,2017,2018 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+ * Copyright © 2016,2017,2018,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
  *
  * This file is part of GNU Mes.
  *
@@ -20,8 +20,56 @@
 
 #include <unistd.h>
 
-int
-isatty (int fd)
+typedef unsigned char cc_t;
+typedef unsigned int speed_t;
+typedef unsigned int tcflag_t;
+
+// Use termio, termios2?
+#define NCCS 19
+struct termios
 {
-  return ioctl (fd, TCGETS, 0) & 0xf0;
+  tcflag_t c_iflag;
+  tcflag_t c_oflag;
+  tcflag_t c_cflag;
+  tcflag_t c_lflag;
+  cc_t c_line;
+  cc_t c_cc[NCCS];
+};
+
+struct ktermios
+{
+  tcflag_t c_iflag;
+  tcflag_t c_oflag;
+  tcflag_t c_cflag;
+  tcflag_t c_lflag;
+  cc_t c_line;
+  cc_t c_cc[NCCS];
+  speed_t c_ispeed;
+  speed_t c_ospeed;
+};
+
+int
+__tcgetattr (int filedes, struct termios *termios_p)
+{
+  struct ktermios kernel_termios;
+  int r = ioctl (filedes, TCGETS, &kernel_termios);
+
+  termios_p->c_iflag = kernel_termios.c_iflag;
+  termios_p->c_oflag = kernel_termios.c_oflag;
+  termios_p->c_cflag = kernel_termios.c_cflag;
+  termios_p->c_lflag = kernel_termios.c_lflag;
+  termios_p->c_line = kernel_termios.c_line;
+#if 0
+  termios_p->c_ispeed = kernel_termios.c_ispeed;
+  termios_p->c_ospeed = kernel_termios.c_ospeed;
+#endif
+  memcpy (&termios_p->c_cc[0], &kernel_termios.c_cc[0], NCCS * sizeof (cc_t));
+  return r;
+}
+
+int
+isatty (int filedes)
+{
+  struct termios term;
+  return __tcgetattr (filedes, &term) == 0;
 }
diff --git a/mes/module/mes/boot-0.scm.in b/mes/module/mes/boot-0.scm.in
index 4ce8610f..b5629a6c 100644
--- a/mes/module/mes/boot-0.scm.in
+++ b/mes/module/mes/boot-0.scm.in
@@ -234,7 +234,7 @@
          (files (if s-index (list-tail %argv (+ s-index 1))
                     (option-ref options '() '())))
          (help? (option-ref options 'help #f))
-         (usage? (and (not help?) (null? files) (not tty?) (not main)))
+         (usage? #f)
          (version? (option-ref options 'version #f)))
     (or
      (and version?