syscalls: Add 'tcgetattr' and 'tcsetattr' bindings.

* guix/build/syscalls.scm (bits->symbols-body, define-bits)
(local-flags): New macros.
(TCSANOW, TCSADRAIN, TCSAFLUSH): New variables.
(<termios>): New record type.
(%termios): New C structure.
(tcgetattr, tcsetattr): New procedures.
* tests/syscalls.scm ("tcgetattr ENOTTY", "tcgetattr")
("tcsetattr"): New tests.

1 files changed, 25 insertions, 0 deletions

diff --git a/tests/syscalls.scm b/tests/syscalls.scm
index 71bcbc4d324..ab1e13984d6 100644
--- a/tests/syscalls.scm
+++ b/tests/syscalls.scm
@@ -259,6 +259,31 @@
              (#f #f)
              (lo (interface-address lo)))))))
 
+(test-equal "tcgetattr ENOTTY"
+  ENOTTY
+  (catch 'system-error
+    (lambda ()
+      (call-with-input-file "/dev/null"
+        (lambda (port)
+          (tcgetattr (fileno port)))))
+    (compose system-error-errno list)))
+
+(test-skip (if (and (file-exists? "/proc/self/fd/0")
+                    (string-prefix? "/dev/pts/" (readlink "/proc/self/fd/0")))
+               0
+               2))
+
+(test-assert "tcgetattr"
+  (let ((termios (tcgetattr 0)))
+    (and (termios? termios)
+         (> (termios-input-speed termios) 0)
+         (> (termios-output-speed termios) 0))))
+
+(test-assert "tcsetattr"
+  (let ((first (tcgetattr 0)))
+    (tcsetattr 0 TCSANOW first)
+    (equal? first (tcgetattr 0))))
+
 (test-assert "terminal-window-size ENOTTY"
   (call-with-input-file "/dev/null"
     (lambda (port)