Save WIP -- I give up for now...

meson.build

@@ -10,6 +10,7 @@ i18n = import('i18n')
 
 subdir('data')
 subdir('src')
+subdir('toolbox')
 subdir('po')
 
 meson.add_install_script('build-aux/meson/postinstall.py')

src/meson.build

@@ -27,6 +27,7 @@ terminal_deps = [
   dependency('vte-2.91-gtk4', version: '>= 0.68.0'),
   dependency('json-glib-1.0', version: '>= 1.4.4'),
   dependency('libpcre2-8'),
+  meson.get_compiler('vala').find_library('posix'),
 ]
 
 # https://github.com/elementary/terminal/blob/d9620eb12331a28c658f97ac9a1bdb809aa90089/meson.build

src/utils/Terminal.vala

@@ -70,4 +70,50 @@ namespace Terminal {
 
     return arr;
   }
+
+  public int get_foreground_process (
+    int terminal_fd,
+    Cancellable? cancellable = null
+  ) {
+    if (!is_flatpak ()) {
+      return Posix.tcgetpgrp (terminal_fd);
+    }
+
+    KeyFile kf = new KeyFile ();
+    kf.load_from_file ("/.flatpak-info", KeyFileFlags.NONE);
+    string host_root = kf.get_string ("Instance", "app-path");
+
+    string[] argv = {
+      "flatpak-spawn",
+      "--host",
+      "%s/bin/terminal-toolbox".printf (host_root),
+      //  "/app/bin/toolbox/terminal-toolbox",
+      "tcgetpgrp",
+      terminal_fd.to_string ()
+    };
+
+    warning ("flatpak-spawn command: %s", string.joinv (" ", argv));
+
+    var launcher = new GLib.SubprocessLauncher(
+      SubprocessFlags.STDOUT_PIPE | SubprocessFlags.STDERR_PIPE
+    );
+
+    launcher.setenv("G_MESSAGES_DEBUG", "false", true);
+
+    var sp = launcher.spawnv(argv);
+
+    if (sp == null) {
+      return -1;
+    }
+
+    string? buf = null;
+    string? err_buf = null;
+    if (!sp.communicate_utf8(null, cancellable, out buf, out err_buf)) {
+      return -1;
+    }
+
+    warning ("PID from terminal-toolbox '%s' -- err %s", buf?.strip (), err_buf);
+
+    return -1;
+  }
 }

src/widgets/Terminal.vala

@@ -40,7 +40,7 @@ public class Terminal.Terminal : Vte.Terminal {
   // Properties
 
   public Scheme scheme  { get; set; }
-  public Pid    pid     { get; protected set; }
+  public Pid    pid     { get; protected set; default = -1; }
 
   // Fields
 
@@ -350,6 +350,41 @@ public class Terminal.Terminal : Vte.Terminal {
     return false;
   }
 
+  public bool get_can_close (out string command = null) {
+    if (this.pid < 0 || this.pty == null) {
+      return true;
+    }
+
+    var fd = this.pty.fd;
+    if (fd == -1) {
+      return true;
+    }
+
+    // Get terminal's foreground process
+    var fgpid = get_foreground_process (fd);
+    if (fgpid == -1) {
+      return false;
+    }
+
+    var filename = "/proc/%d/cmdline".printf (fgpid);
+    string? data = null;
+
+    try {
+      if (!FileUtils.get_contents (filename, out data, null)) {
+        // There is something running, we just failed to check what it is
+        return false;
+      }
+
+      command = Filename.to_utf8 (data, data.length, null, null);
+      warning ("Terminal running command %s", command);
+    }
+    catch (Error e) {
+      warning ("%s", e.message);
+    }
+
+    return true;
+  }
+
   //  private void on_drag_data_received(
   //    Gdk.DragContext _context,
   //    int _x,

src/widgets/Window.vala

@@ -214,6 +214,18 @@ public class Terminal.Window : Adw.ApplicationWindow {
       return w.tab_view;
     });
 
+    this.tab_view.close_page.connect ((page) => {
+      var terminal = (page.get_child () as TerminalTab)?.terminal;
+      bool can_close = true;
+
+      if (terminal != null) {
+        can_close = terminal.get_can_close ();
+      }
+
+      this.tab_view.close_page_finish (page, can_close);
+      return true;
+    });
+
     // Close the window if all tabs were closed
     this.tab_view.notify["n-pages"].connect (() => {
       if (this.tab_view.n_pages < 1) {

toolbox/main.c

+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <pwd.h>
+#include <sys/types.h>
+#include <stdarg.h>
+
+/**
+ * This is a simple program meant to be launched with flatpak-spawn --host to
+ * retrieve host information Flatpak'ed apps don't have access to. The original
+ * idea for this program came from
+ * https://github.com/gnunn1/tilix/blob/master/experimental/flatpak/tilix-flatpak-toolbox.c
+ */
+
+int die (int code, char *fmt, ...) __attribute__((format(printf,2,0)));
+
+int die (int code, char *fmt, ...) {
+  va_list list;
+  va_start (list, fmt);
+  vfprintf (stderr, fmt, list);
+  return code;
+}
+
+int main (int argc, const char *argv[]) {
+  if (argc < 2) {
+    return die (1, "Not enough arguments.\n");
+  }
+
+  if (strcmp (argv[1], "tcgetpgrp") == 0) {
+    if (argc != 3) {
+      return die (1, "Missing argument `fd` for tcgetpgrp.\n");
+    }
+
+    unsigned long _fd = (int) strtoul (argv[2], NULL, 10);
+    if (_fd > __INT_MAX__) {
+      return die (1, "Invalid fd.\n");
+    }
+    int fd = (int) _fd;
+
+    pid_t pid = tcgetpgrp (fd);
+
+    printf ("pid:%d (fd %d)\n", pid, fd);
+
+    return 0;
+  }
+  else {
+    return die (1, "Unknown command '%s'.\n", argv[1]);
+  }
+
+  return 0;
+}

toolbox/meson.build

+toolbox_sources = files(
+  'main.c',
+)
+
+toolbox_deps = []
+
+toolbox_build_args = ['-Werror', '-Wextra', '-Wall']
+
+executable('terminal-toolbox',
+  toolbox_sources,
+  c_args: toolbox_build_args,
+  dependencies: toolbox_deps,
+  install: true,
+)