Added some more server socket fun and examples. (0.27.0)

examples/extra/pcsc2_example.fun

@@ -0,0 +1,53 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2025-10-04
+ */
+
+// Example using stdlib PCSC2 class.
+// Establish context, list readers, connect to first (if any),
+// send a sample SELECT MF APDU, print results, and clean up.
+
+#include <io/pcsc2.fun>
+
+pc = PCSC2()
+
+ctx = pc.establish()
+print("ctx=" + to_string(ctx))
+
+readers = pc.list_readers(ctx)
+print("readers=" + to_string(readers))
+
+number h = 0
+if len(readers) > 0
+  h = pc.connect(ctx, readers[1])
+  print("handle=" + to_string(h))
+
+  if h != 0
+    // APDU 1: SELECT applet by AID (should return 251 data bytes, constant)
+    resp = pc.transmit_hex(h, "00a4040c0cD2760001354B414E4D30310000")
+    print(to_string(resp))
+    print("resp.data_hex=" + resp["data_hex"]) 
+    print("resp.sw1=" + to_string(resp["sw1"]) + " sw2=" + to_string(resp["sw2"]) + " code=" + to_string(resp["code"]))
+    number dlen1 = len(resp["data_hex"]) / 2
+    print("SELECT AID data length=" + to_string(dlen1) + " (expected 251)")
+
+    // APDU 2: GET CHALLENGE 8 (should return 8 random bytes)
+    resp = pc.transmit_hex(h, "0084000008")
+    print(to_string(resp))
+    print("resp.data_hex=" + resp["data_hex"]) 
+    print("resp.sw1=" + to_string(resp["sw1"]) + " sw2=" + to_string(resp["sw2"]) + " code=" + to_string(resp["code"]))
+    number dlen2 = len(resp["data_hex"]) / 2
+    print("GET CHALLENGE data length=" + to_string(dlen2) + " (expected 8)")
+
+    _ = pc.disconnect(h)
+
+_ = pc.release(ctx)
+print("done")

examples/extra/pcsc_demo.fun

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+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2025-10-02
+ */
+
+// PCSC demo using stdlib PCSC class.
+// Establishes context, lists readers, optionally connects to the first,
+// transmits a sample APDU (SELECT MF), and cleans up.
+
+#include <io/pcsc.fun>
+
+pc = PCSC()
+
+ctx = pc.establish()
+print("ctx=" + to_string(ctx))
+
+readers = pc.list_readers(ctx)
+print("readers=" + to_string(readers))
+
+number h = 0
+if len(readers) > 0
+  // Connect to first reader
+  h = pc.connect(ctx, readers[1])
+  print("handle=" + to_string(h))
+
+  if h != 0
+    // Sample APDU: SELECT MF (00 A4 00 00 02 3F 00)
+    resp = pc.transmit_hex(h, "00A40000023F00")
+    // Print hex data and SW
+    print("resp.data_hex=" + resp["data_hex"])
+    print("resp.sw1=" + to_string(resp["sw1"]) + " sw2=" + to_string(resp["sw2"]) + " code=" + to_string(resp["code"]))
+
+    _ = pc.disconnect(h)
+
+_ = pc.release(ctx)
+print("done")

examples/extra/tcp_echo_server.fun

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+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2025-10-13
+ */
+
+// Simple TCP echo server using built-in socket ops.
+// Listens on localhost:12345 and echoes a single line/request back to each client.
+
+port = 12345
+backlog = 16
+
+listen_fd = tcp_listen(port, backlog)
+if (listen_fd <= 0)
+  print("tcp_listen failed")
+  exit(1)
+
+print("Echo server listening on port " + to_string(port))
+
+while (true)
+  client = tcp_accept(listen_fd)
+  if (client > 0)
+    data = sock_recv(client, 4096)
+    if (len(data) > 0)
+      // Echo back exactly what we received
+      sock_send(client, data)
+    sock_close(client)
+
+// Not reached in this example, but here for completeness
+sock_close(listen_fd)

examples/extra/tcp_echo_server_class.fun

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+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2025-10-13
+ */
+
+// Echo server using the stdlib TcpServer class.
+// Make sure FUN_LIB_DIR points to the ./lib directory containing io/socket.fun.
+// Example:
+//   FUN_LIB_DIR="$(pwd)/lib" ./build/fun ./examples/tcp_echo_server_class.fun
+
+include <io/socket.fun>
+
+print("Starting echo server at localhost:12345")
+
+server = TcpServer(12345, 16)
+
+if (server.listen() <= 0)
+  print("Listen failed!")
+  exit(1)
+else
+  print("Echo server (class) listening on port 12345")
+
+// Serve clients forever, echoing back what they send.
+server.serve_forever(4096)