tty: implement binary I/O terminal mode

Introduce a uv_tty_mode_t enum for uv_tty_set_mode(), with backward
compatible values.  Add a new mode UV_TTY_MODE_IO, which uses
cfmakeraw() internally.

PR-URL: https://github.com/libuv/libuv/pull/86
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Saúl Ibarra Corretgé <saghul@gmail.com>

docs/src/tty.rst

@@ -16,6 +16,22 @@ Data types
 
     TTY handle type.
 
+.. c:type:: uv_tty_mode_t
+
+    TTY mode type:
+
+    ::
+
+        typedef enum {
+            /* Initial/normal terminal mode */
+            UV_TTY_MODE_NORMAL,
+            /* Raw input mode (On Windows, ENABLE_WINDOW_INPUT is also enabled) */
+            UV_TTY_MODE_RAW,
+            /* Binary-safe I/O mode for IPC (Unix-only) */
+            UV_TTY_MODE_IO
+        } uv_tty_mode_t;
+
+
 
 Public members
 ^^^^^^^^^^^^^^
@@ -43,9 +59,9 @@ API
     .. note::
         TTY streams which are not readable have blocking writes.
 
-.. c:function:: int uv_tty_set_mode(uv_tty_t*, int mode)
+.. c:function:: int uv_tty_set_mode(uv_tty_t*, uv_tty_mode_t mode)
 
-    Set the TTY mode. 0 for normal, 1 for raw.
+    Set the TTY using the specified terminal mode.
 
 .. c:function:: int uv_tty_reset_mode(void)
 

include/uv.h

@@ -628,11 +628,30 @@ struct uv_tty_s {
   UV_TTY_PRIVATE_FIELDS
 };
 
+typedef enum {
+  /* Initial/normal terminal mode */
+  UV_TTY_MODE_NORMAL,
+  /* Raw input mode (On Windows, ENABLE_WINDOW_INPUT is also enabled) */
+  UV_TTY_MODE_RAW,
+  /* Binary-safe I/O mode for IPC (Unix-only) */
+  UV_TTY_MODE_IO
+} uv_tty_mode_t;
+
 UV_EXTERN int uv_tty_init(uv_loop_t*, uv_tty_t*, uv_file fd, int readable);
-UV_EXTERN int uv_tty_set_mode(uv_tty_t*, int mode);
+UV_EXTERN int uv_tty_set_mode(uv_tty_t*, uv_tty_mode_t mode);
 UV_EXTERN int uv_tty_reset_mode(void);
 UV_EXTERN int uv_tty_get_winsize(uv_tty_t*, int* width, int* height);
 
+#ifdef __cplusplus
+}  /* extern "C" */
+
+inline int uv_tty_set_mode(uv_tty_t* handle, int mode) {
+  return uv_tty_set_mode(handle, static_cast<uv_tty_mode_t>(mode));
+}
+
+extern "C" {
+#endif
+
 UV_EXTERN uv_handle_type uv_guess_handle(uv_file file);
 
 /*

src/unix/tty.c

@@ -98,19 +98,19 @@ skip:
     uv__nonblock(fd, 1);
 
   uv__stream_open((uv_stream_t*) tty, fd, flags);
-  tty->mode = 0;
+  tty->mode = UV_TTY_MODE_NORMAL;
 
   return 0;
 }
 
 
-int uv_tty_set_mode(uv_tty_t* tty, int mode) {
-  struct termios raw;
+int uv_tty_set_mode(uv_tty_t* tty, uv_tty_mode_t mode) {
+  struct termios tmp;
   int fd;
 
   fd = uv__stream_fd(tty);
 
-  if (mode && tty->mode == 0) {  /* on */
+  if (tty->mode == UV_TTY_MODE_NORMAL && mode != UV_TTY_MODE_NORMAL) {
     if (tcgetattr(fd, &tty->orig_termios))
       return -errno;
 
@@ -121,27 +121,30 @@ int uv_tty_set_mode(uv_tty_t* tty, int mode) {
       orig_termios_fd = fd;
     }
     uv_spinlock_unlock(&termios_spinlock);
-
-    raw = tty->orig_termios;
-    raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
-    raw.c_oflag |= (ONLCR);
-    raw.c_cflag |= (CS8);
-    raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
-    raw.c_cc[VMIN] = 1;
-    raw.c_cc[VTIME] = 0;
-
-    /* Put terminal in raw mode after draining */
-    if (tcsetattr(fd, TCSADRAIN, &raw))
-      return -errno;
-
-    tty->mode = 1;
-  } else if (mode == 0 && tty->mode) {  /* off */
-    /* Put terminal in original mode after flushing */
-    if (tcsetattr(fd, TCSAFLUSH, &tty->orig_termios))
-      return -errno;
-    tty->mode = 0;
   }
 
+  tmp = tty->orig_termios;
+  switch (mode) {
+    case UV_TTY_MODE_NORMAL:
+      break;
+    case UV_TTY_MODE_RAW:
+      tmp.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
+      tmp.c_oflag |= (ONLCR);
+      tmp.c_cflag |= (CS8);
+      tmp.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
+      tmp.c_cc[VMIN] = 1;
+      tmp.c_cc[VTIME] = 0;
+      break;
+    case UV_TTY_MODE_IO:
+      cfmakeraw(&tmp);
+      break;
+  }
+
+  /* Apply changes after draining */
+  if (tcsetattr(fd, TCSADRAIN, &tmp))
+    return -errno;
+
+  tty->mode = mode;
   return 0;
 }
 

src/win/tty.c

@@ -170,7 +170,7 @@ int uv_tty_init(uv_loop_t* loop, uv_tty_t* tty, uv_file fd, int readable) {
 }
 
 
-int uv_tty_set_mode(uv_tty_t* tty, int mode) {
+int uv_tty_set_mode(uv_tty_t* tty, uv_tty_mode_t mode) {
   DWORD flags;
   unsigned char was_reading;
   uv_alloc_cb alloc_cb;
@@ -185,12 +185,15 @@ int uv_tty_set_mode(uv_tty_t* tty, int mode) {
     return 0;
   }
 
-  if (mode) {
-    /* Raw input */
-    flags = ENABLE_WINDOW_INPUT;
-  } else {
-    /* Line-buffered mode. */
+  switch (mode) {
+    case UV_TTY_MODE_NORMAL:
       flags = ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT;
+      break;
+    case UV_TTY_MODE_RAW:
+      flags = ENABLE_WINDOW_INPUT;
+      break;
+    case UV_TTY_MODE_IO:
+      return UV_ENOTSUP;
   }
 
   if (!SetConsoleMode(tty->handle, flags)) {