From a6654e1c5fb41db53cd2bc8ec6e06f2adf02f388 Mon Sep 17 00:00:00 2001
From: Maksym Vorobiov <maxim.vorobjov@gmail.com>
Date: Mon, 18 Nov 2019 23:24:01 +0200
Subject: [PATCH] add elementary wasi support

---
 src/tty/mod.rs  |  5 +++++
 src/tty/wasi.rs | 16 ++++++++++++++++
 2 files changed, 21 insertions(+)
 create mode 100644 src/tty/wasi.rs

diff --git a/src/tty/mod.rs b/src/tty/mod.rs
index db9dfa55..edc41ed8 100644
--- a/src/tty/mod.rs
+++ b/src/tty/mod.rs
@@ -17,6 +17,11 @@ mod unix;
 #[cfg(unix)]
 pub use self::unix::*;
 
+#[cfg(target_os="wasi")]
+mod wasi;
+#[cfg(target_os="wasi")]
+pub use self::wasi::*;
+
 #[cfg(windows)]
 mod windows;
 #[cfg(windows)]
diff --git a/src/tty/wasi.rs b/src/tty/wasi.rs
new file mode 100644
index 00000000..8bb756f9
--- /dev/null
+++ b/src/tty/wasi.rs
@@ -0,0 +1,16 @@
+extern crate libc;
+use super::{Width, Height};
+
+/// For WASI so far it will return none
+///
+/// For background https://github.com/WebAssembly/WASI/issues/42
+pub fn terminal_size() -> Option<(Width, Height)> {
+    return None;
+}
+
+/// This is inherited from unix and will work only when wasi executed on unix.
+/// 
+/// For background https://github.com/WebAssembly/WASI/issues/42
+pub fn move_cursor_up(n: usize) -> String {
+    format!("\x1B[{}A", n)
+}