initial commit

1 files changed, 100 insertions, 0 deletions

diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..7f372c1
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,100 @@
+use std::io::{self, Read, Write, IsTerminal};
+use std::os::unix::io::AsRawFd;
+use termios::*;
+
+struct ScopedRawMode {
+    fd: i32,
+    settings: Termios,
+}
+
+impl Drop for ScopedRawMode {
+    fn drop(&mut self) {
+        self.disable();
+    }
+}
+
+impl ScopedRawMode {
+    fn on_fd(fd: i32) -> Self {
+        let mut termios = Termios::from_fd(fd).unwrap();
+        let settings = termios.clone();
+        cfmakeraw(&mut termios);
+        tcsetattr(fd, TCSANOW, &termios).unwrap();
+        Self { fd, settings }
+    }
+
+    fn disable(&self) {
+        tcsetattr(self.fd, TCSANOW, &self.settings).unwrap();
+    }
+}
+
+macro_rules! print {
+    ($($x:tt)*) => {{
+        write!(io::stdout(), $($x)*).unwrap();
+        io::stdout().flush().unwrap();
+    }}
+}
+
+fn main() {
+    let stdin = io::stdin();
+    let stdout = io::stdout();
+
+    if !stdin.is_terminal() {
+        println!("need to run in a tty");
+        return;
+    }
+
+    let fd = stdin.as_raw_fd();
+    let _scoped_raw = ScopedRawMode::on_fd(fd); // needs to be a var, gets dropped on scope exit,
+                                                // even if something panics
+
+    let mut stdin = stdin.lock();
+    let mut stdout = stdout.lock();
+
+    let mut buffer = [0u8; 1];
+
+    loop {
+        let Ok(_) = stdin.read_exact(&mut buffer) else {
+            break;
+        };
+
+        match buffer[0] {
+            // EOF
+            4 => {
+                break;
+            }
+
+            // Enter
+            b'\r' => {
+                println!("\r");
+            }
+
+            // Backspace (127 on most systems)
+            127 => {
+                write!(stdout, "\x08 \x08").unwrap();
+                stdout.flush().unwrap();
+            }
+
+            // Escape sequence
+            27 => {
+                let mut seq = [0u8; 2];
+                stdin.read_exact(&mut seq).unwrap();
+
+                if seq[0] == b'[' {
+                    match seq[1] {
+                        b'A' => print!("Up"),
+                        b'B' => print!("Down"),
+                        b'C' => print!("Right"),
+                        b'D' => print!("Left"),
+                        _ => {}
+                    }
+                }
+            }
+
+            // Normal character
+            x => {
+                stdout.write(&[x]).unwrap();
+                stdout.flush().unwrap();
+            }
+        }
+    }
+}