1 files changed, 114 insertions, 0 deletions
diff --git a/examples/subprocess/main.cc b/examples/subprocess/main.cc
new file mode 100644
index 00000000..f72526ee
--- /dev/null
+++ b/examples/subprocess/main.cc
@@ -0,0 +1,114 @@
+/* Copyright (C) 2023 The gtkmm Development Team
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <giomm.h>
+#include <iostream>
+
+namespace
+{
+int finish_pending = 0;
+
+void on_communicate_finished(Glib::RefPtr<Gio::AsyncResult>& result,
+  const Glib::RefPtr<Gio::Subprocess>& subprocess, const Glib::ustring& heading)
+{
+  try
+  {
+  std::cout << "\n" << heading << "\n";
+  auto [stdout_buf, stderr_buf] = subprocess->communicate_utf8_finish(result);
+  std::cout << "stdout_buf: " << stdout_buf << "\n"
+            << "stderr_buf: " << stderr_buf << "\n";
+  }
+  catch (const Glib::Error& error)
+  {
+    std::cerr << "on_communicate_finished(), Glib::Error: " << error.what() << std::endl;
+  }
+  catch (const std::exception& error)
+  {
+    std::cerr << "on_communicate_finished(), std::exception: " << error.what() << std::endl;
+  }
+  --finish_pending;
+}
+} // anonymous namespace
+
+int main(int argc, char** argv)
+{
+  Gio::init();
+
+  if (argc < 3)
+  {
+    std::cerr << "Usage: " << argv[0] << " input-data command [arguments]...\n";
+    return 1;
+  }
+
+  // Three character encodings can be involved:
+  // 1. The encoding in the user's preferred locale.
+  // 2. The filename encoding, used by GLib.
+  // 3. UTF-8.
+  // The encoding used in argv is determined by the operating system.
+  // It's assumed to be the encoding in the user's preferred locale,
+  // which is also the C and C++ global locale. See the documentation of
+  // Glib::set_init_to_users_preferred_locale().
+  try
+  {
+    const auto stdin_buf = Glib::locale_to_utf8(argv[1]);
+
+    std::vector<std::string> arg_vector;
+    for (int i = 2; i < argc; ++i)
+      arg_vector.push_back(Glib::filename_from_utf8(Glib::locale_to_utf8(argv[i])));
+
+    Gio::Subprocess::Flags flags =
+      Gio::Subprocess::Flags::STDOUT_PIPE | Gio::Subprocess::Flags::STDERR_PIPE;
+    if (!stdin_buf.empty())
+      flags |= Gio::Subprocess::Flags::STDIN_PIPE;
+
+    // This example would be easier with the synchronous communicate_utf8().
+
+    // Without SubprocessLauncher.
+    auto subprocess = Gio::Subprocess::create(arg_vector, flags);
+    ++finish_pending;
+    subprocess->communicate_utf8_async(stdin_buf,
+      [&subprocess](Glib::RefPtr<Gio::AsyncResult>& result)
+      {
+        on_communicate_finished(result, subprocess, "Without SubprocessLauncher");
+      });
+
+    // With SubprocessLauncher.
+    auto launcher = Gio::SubprocessLauncher::create(flags);
+    auto spawned_subprocess = launcher->spawn(arg_vector);
+    ++finish_pending;
+    spawned_subprocess->communicate_utf8_async(stdin_buf,
+      [&spawned_subprocess](Glib::RefPtr<Gio::AsyncResult>& result)
+      {
+        on_communicate_finished(result, spawned_subprocess, "With SubprocessLauncher");
+      });
+  }
+  catch (const Glib::Error& error)
+  {
+    std::cerr << "Glib::Error: " << error.what() << std::endl;
+    return 1;
+  }
+  catch (const std::exception& error)
+  {
+    std::cerr << "std::exception: " << error.what() << std::endl;
+    return 1;
+  }
+
+  // Wait for on_communicate_finished() to finish.
+  auto main_context = Glib::MainContext::get_thread_default();
+  while (finish_pending > 0)
+    main_context->iteration(true);
+  return 0;
+}