Upload spectral-pty/src/unix.rs

spectral-pty/src/unix.rs

@@ -0,0 +1,89 @@
+use libc;
+use std::fs::File;
+use std::io::{self, Read, Write};
+use std::os::fd::{AsRawFd, FromRawFd, RawFd};
+
+use crate::PtyTrait;
+
+pub struct Pty {
+    pub master: File,
+    pub child_pid: libc::pid_t,
+    pub shell_path: String,
+}
+
+impl Pty {
+    pub fn new(cols: u16, rows: u16, shell: Option<&str>) -> io::Result<Self> {
+        let shell_path = shell.map(|s| s.to_string()).unwrap_or_else(|| {
+            std::env::var("SHELL").unwrap_or_else(|_| "/bin/sh".to_string())
+        });
+        let shell = shell_path.as_str();
+
+        let mut winsize = libc::winsize {
+            ws_row: rows, ws_col: cols, ws_xpixel: 0, ws_ypixel: 0,
+        };
+
+        let mut master_fd: RawFd = -1;
+        let mut slave_fd: RawFd = -1;
+
+        unsafe {
+            if libc::openpty(
+                &mut master_fd, &mut slave_fd,
+                std::ptr::null_mut(), std::ptr::null(), &mut winsize,
+            ) != 0 { return Err(io::Error::last_os_error()); }
+        }
+
+        let child_pid = unsafe { libc::fork() };
+        if child_pid < 0 { return Err(io::Error::last_os_error()); }
+
+        if child_pid == 0 {
+            unsafe {
+                libc::close(master_fd);
+                libc::setsid();
+                libc::ioctl(slave_fd, libc::TIOCSCTTY, 0);
+                libc::dup2(slave_fd, 0);
+                libc::dup2(slave_fd, 1);
+                libc::dup2(slave_fd, 2);
+                if slave_fd > 2 { libc::close(slave_fd); }
+                let shell_c = std::ffi::CString::new(shell).unwrap();
+                let arg0_c = std::ffi::CString::new("-").unwrap();
+                libc::execvp(shell_c.as_ptr(), [arg0_c.as_ptr(), std::ptr::null()].as_ptr());
+                libc::_exit(1);
+            }
+        }
+
+        unsafe { libc::close(slave_fd); }
+        let master = unsafe { File::from_raw_fd(master_fd) };
+
+        Ok(Self { master, child_pid, shell_path })
+    }
+}
+
+impl PtyTrait for Pty {
+    fn resize(&mut self, cols: u16, rows: u16) -> io::Result<()> {
+        let winsize = libc::winsize {
+            ws_row: rows, ws_col: cols, ws_xpixel: 0, ws_ypixel: 0,
+        };
+        let fd = self.master.as_raw_fd();
+        unsafe {
+            if libc::ioctl(fd, libc::TIOCSWINSZ, &winsize) != 0 {
+                return Err(io::Error::last_os_error());
+            }
+        }
+        Ok(())
+    }
+
+    fn pid(&self) -> Option<u32> { Some(self.child_pid as u32) }
+}
+
+impl Read for Pty {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> { self.master.read(buf) }
+}
+
+impl Write for Pty {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> { self.master.write(buf) }
+    fn flush(&mut self) -> io::Result<()> { self.master.flush() }
+}
+
+impl Drop for Pty {
+    fn drop(&mut self) { unsafe { libc::kill(self.child_pid, libc::SIGHUP); } }
+}