Add TIOCGWINSZ ioctl (#54)

discover/discover.ml

@@ -281,8 +281,9 @@ let features =
     "TTY_IOCTL", L[
       fd_int;
       I "termios.h"; I "sys/ioctl.h";
+      T "struct winsize";
       S "ioctl"; S "tcsetattr"; S "tcgetattr";
-      D "CRTSCTS"; D "TCSANOW"; D "TIOCMGET"; D "TIOCMSET"; D "TIOCMBIC"; D "TIOCMBIS";
+      D "CRTSCTS"; D "TCSANOW"; D "TIOCMGET"; D "TIOCMSET"; D "TIOCMBIC"; D "TIOCMBIS"; D "TIOCGWINSZ"
     ];
     "TTYNAME", L[ fd_int; I "unistd.h"; S "ttyname"; ];
     "CTERMID", L[ I "stdio.h"; S "ctermid"; V "L_ctermid"; ];

dune-project

@@ -38,6 +38,7 @@
   "Roman Vorobets"
   "Stéphane Glondu"
   "Sylvain Le Gall"
+  "Teague Hansen"
   "ygrek"
   "Zhenya Lykhovyd"
  )

extunix.opam

@@ -25,6 +25,7 @@ authors: [
   "Roman Vorobets"
   "Stéphane Glondu"
   "Sylvain Le Gall"
+  "Teague Hansen"
   "ygrek"
   "Zhenya Lykhovyd"
 ]

src/extUnix.pp.ml

@@ -793,6 +793,12 @@ external tiocmbic : Unix.file_descr -> int -> unit = "caml_extunix_ioctl_TIOCMBI
 (** Set the indicated modem bits. See TIOCMBIS in tty_ioctl(4). *)
 external tiocmbis : Unix.file_descr -> int -> unit = "caml_extunix_ioctl_TIOCMBIS"
 
+(** [tiocgwinsz fd] returns a tuple [(cols, rows, xpixel, ypixel)] representing
+    the size of the character device. [cols] is the number of character columns,
+    [rows] is the number of character rows, [xpixel] is width of the device in
+    pixels, and [ypixel] is the height of the device in pixels. *)
+external tiocgwinsz : Unix.file_descr -> (int * int * int * int) = "caml_extunix_ioctl_TIOCGWINSZ"
+
 ]
 
 end (* module Ioctl *)

src/tty_ioctl.c

@@ -33,6 +33,27 @@ CAMLprim value caml_extunix_ioctl_##cmd(value v_fd, value v_arg) \
   CAMLreturn(Val_unit); \
 }
 
+CAMLprim value caml_extunix_ioctl_TIOCGWINSZ(value v_fd)
+{
+    CAMLparam1(v_fd);
+    CAMLlocal1(result);
+
+    struct winsize ws;
+
+    int r = ioctl(Int_val(v_fd), TIOCGWINSZ, &ws);
+    if (r < 0) {
+        uerror("ioctl", caml_copy_string("TIOCGWINSZ"));
+    }
+
+    result = caml_alloc_tuple(4);
+    Store_field(result, 0, Val_int(ws.ws_col));
+    Store_field(result, 1, Val_int(ws.ws_row));
+    Store_field(result, 2, Val_int(ws.ws_xpixel));
+    Store_field(result, 3, Val_int(ws.ws_ypixel));
+
+    CAMLreturn(result);
+}
+
 CAMLprim value caml_extunix_ioctl_TIOCMGET(value v_fd)
 {
   CAMLparam1(v_fd);
@@ -47,4 +68,3 @@ TTY_IOCTL_INT(TIOCMBIC)
 TTY_IOCTL_INT(TIOCMBIS)
 
 #endif
-