NetDesk 1.5.0 — source release

host/pty_session.py

@@ -0,0 +1,112 @@
+"""Interactive command terminal for the NetDesk host ("cmd").
+
+Spawns a shell and streams its output, so a connected viewer gets a working
+console: run commands and see their output live (dir, ipconfig, ping, python
+scripts, git, etc.). Uses a pipe rather than a full pseudo-console — that covers
+command execution; full-screen TUI apps (vim, a nested shell UI) would need a
+ConPTY and are a future enhancement.
+
+Wire protocol (host side):
+  viewer -> host : {"t":"term.open","tid":N}              open a shell
+  viewer -> host : {"t":"term.data","tid":N,"d":"<text>"} send keystrokes/commands
+  viewer -> host : {"t":"term.resize","tid":N,"cols":C,"rows":R}
+  viewer -> host : {"t":"term.close","tid":N}
+  host  -> viewer: {"t":"term.data","tid":N,"d":"<text>"}  shell output (streamed)
+  host  -> viewer: {"t":"term.exit","tid":N}               shell ended
+
+Developed by Akronlogic.
+"""
+import os
+import subprocess
+import threading
+
+CREATE_NO_WINDOW = 0x08000000
+
+
+class TerminalSession:
+    """One shell process. `on_output(text: str)` is invoked from a reader
+    thread as the shell produces output; it is called once with "" when the
+    shell exits."""
+
+    def __init__(self, on_output, shell=None, cwd=None):
+        self._on_output = on_output
+        shell = shell or os.environ.get("COMSPEC", "cmd.exe")
+        self._p = subprocess.Popen(
+            shell,
+            stdin=subprocess.PIPE,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.STDOUT,
+            bufsize=0,
+            cwd=cwd,
+            creationflags=CREATE_NO_WINDOW if os.name == "nt" else 0,
+        )
+        self._alive = True
+        self._reader = threading.Thread(target=self._pump, daemon=True)
+        self._reader.start()
+
+    def _pump(self):
+        try:
+            while True:
+                chunk = self._p.stdout.read(4096)
+                if not chunk:
+                    break
+                try:
+                    self._on_output(chunk.decode("utf-8", "replace"))
+                except Exception:
+                    pass
+        finally:
+            self._alive = False
+            try:
+                self._on_output("")  # EOF -> shell closed
+            except Exception:
+                pass
+
+    def write(self, data):
+        """Send keystrokes / a command line (include the trailing \\r\\n)."""
+        if isinstance(data, str):
+            data = data.encode("utf-8", "replace")
+        try:
+            self._p.stdin.write(data)
+            self._p.stdin.flush()
+            return True
+        except Exception:
+            return False
+
+    def resize(self, cols, rows):
+        # Pipe mode has no window size; accepted for API parity (ConPTY later).
+        return None
+
+    @property
+    def alive(self):
+        return self._alive and self._p.poll() is None
+
+    def close(self):
+        self._alive = False
+        try:
+            self._p.stdin.close()
+        except Exception:
+            pass
+        try:
+            self._p.terminate()
+        except Exception:
+            pass
+
+
+if __name__ == "__main__":
+    import time
+
+    buf = []
+    term = TerminalSession(on_output=buf.append)
+    time.sleep(0.3)
+    term.write("echo NETDESK_TERM_OK_777\r\n")
+    time.sleep(0.6)
+    term.write("cd\r\n")
+    time.sleep(0.4)
+    term.write("exit\r\n")
+    time.sleep(0.4)
+    term.close()
+    text = "".join(buf)
+    ok = "NETDESK_TERM_OK_777" in text
+    print("SELFTEST", "PASS" if ok else "FAIL", "| chars:", len(text))
+    if not ok:
+        print(text[:800])