is-a-tty?

lib/chibi/filesystem.module

@@ -20,7 +20,7 @@
           open/read        open/write             open/read-write
           open/create      open/exclusive         open/truncate
           open/append      open/non-block
-          )
+          is-a-tty?)
   (import-immutable (scheme))
   (include-shared "filesystem")
   (include "filesystem.scm"))

lib/chibi/filesystem.stub

@@ -113,3 +113,6 @@
 (define-c-const int (open/truncate "O_TRUNC"))
 (define-c-const int (open/append "O_APPEND"))
 (define-c-const int (open/non-block "O_NONBLOCK"))
+
+(define-c boolean (is-a-tty? "isatty") (port-or-fd))
+

tools/genstubs.scm

@@ -507,7 +507,10 @@
       (cat "sexp_concat_env_string(" val ")"))
      ((string-type? base)
       (cat "sexp_string_data(" val ")"))
-     ((memq base '(port input-port output-port))
+     ((eq? base 'port-or-fd)
+      (cat "(sexp_portp(" val ") ? fileno(sexp_port_stream(" val "))"
+           " : sexp_unbox_fixnum(" val "))"))
+     ((port-type? base)
       (cat "sexp_port_stream(" val ")"))
      (else
       (let ((ctype (assq base *types*)))
@@ -607,6 +610,9 @@
           (cat "  if (! sexp_nullp(res))\n"
                "    return sexp_type_exception(ctx, \"not a list of "
                (type-name type) "s\", " arg ");\n")))
+     ((eq? base-type 'port-or-fd)
+      (cat "if (! (sexp_portp(" arg ") || sexp_fixnump(" arg ")))\n"
+           "  return sexp_type_exception(ctx, \"not a port of file descriptor\"," arg ");\n"))
      ((or (int-type? base-type)
           (float-type? base-type)
           (string-type? base-type)