[gnome-builder] libide-io: add shell routines to libide-io

[Christian Hergert <chergert src gnome org>]

commit 24891ddf477fd2f7035c106e3e466be3eecc5dc5
Author: Christian Hergert <chergert redhat com>
Date:   Mon Jul 11 16:37:43 2022 -0700

    libide-io: add shell routines to libide-io
    
    These are useful lower in our stack.

 src/libide/io/ide-shell-private.h |  30 +++++++
 src/libide/io/ide-shell.c         | 164 +++++++++++++++++++++++++++++++++++++-
 src/libide/io/ide-shell.h         |  12 ++-
 src/libide/io/meson.build         |   1 +
 4 files changed, 202 insertions(+), 5 deletions(-)
---
diff --git a/src/libide/io/ide-shell-private.h b/src/libide/io/ide-shell-private.h
new file mode 100644
index 000000000..a10695804
--- /dev/null
+++ b/src/libide/io/ide-shell-private.h
@@ -0,0 +1,30 @@
+/* ide-shell-private.h
+ *
+ * Copyright 2018-2019 Christian Hergert <chergert redhat com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include "ide-shell.h"
+
+G_BEGIN_DECLS
+
+void _ide_guess_shell     (void);
+void _ide_guess_user_path (void);
+
+G_END_DECLS
diff --git a/src/libide/io/ide-shell.c b/src/libide/io/ide-shell.c
index 12f9ecb9a..b188167cd 100644
--- a/src/libide/io/ide-shell.c
+++ b/src/libide/io/ide-shell.c
@@ -18,9 +18,16 @@
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
+#define G_LOG_DOMAIN "ide-shell"
+
 #include "config.h"
 
-#include "ide-shell.h"
+#include <libide-threading.h>
+
+#include "ide-shell-private.h"
+
+static const char *user_shell = "/bin/sh";
+static const char *user_default_path = SAFE_PATH;
 
 gboolean
 ide_shell_supports_dash_c (const char *shell)
@@ -45,3 +52,158 @@ ide_shell_supports_dash_login (const char *shell)
          strcmp (shell, "zsh") == 0 || g_str_has_suffix (shell, "/zsh") ||
          strcmp (shell, "sh") == 0 || g_str_has_suffix (shell, "/sh");
 }
+
+static void
+ide_guess_shell_communicate_cb (GObject      *object,
+                                GAsyncResult *result,
+                                gpointer      user_data)
+{
+  IdeSubprocess *subprocess = (IdeSubprocess *)object;
+  g_autoptr(GError) error = NULL;
+  g_autofree gchar *stdout_buf = NULL;
+  const char *key = user_data;
+
+  g_assert (IDE_IS_SUBPROCESS (subprocess));
+  g_assert (G_IS_ASYNC_RESULT (result));
+  g_assert (key != NULL);
+
+  if (!ide_subprocess_communicate_utf8_finish (subprocess, result, &stdout_buf, NULL, &error))
+    {
+      g_warning ("Failure to parse host information: %s", error->message);
+      return;
+    }
+
+  if (stdout_buf != NULL)
+    g_strstrip (stdout_buf);
+
+  g_debug ("Guessed %s as \"%s\"", key, stdout_buf);
+
+  if (ide_str_equal0 (key, "SHELL"))
+    {
+      if (stdout_buf[0] == '/')
+        user_shell = g_steal_pointer (&stdout_buf);
+    }
+  else if (ide_str_equal0 (key, "PATH"))
+    {
+      if (!ide_str_empty0 (stdout_buf))
+        user_default_path = g_steal_pointer (&stdout_buf);
+    }
+}
+
+void
+_ide_guess_shell (void)
+{
+  g_autoptr(IdeSubprocessLauncher) launcher = NULL;
+  g_autoptr(IdeSubprocess) subprocess = NULL;
+  g_autofree gchar *command = NULL;
+  g_autoptr(GError) error = NULL;
+  g_auto(GStrv) argv = NULL;
+
+#ifdef __APPLE__
+  command = g_strdup_printf ("sh -c 'dscacheutil -q user -a name %s | grep ^shell: | cut -f 2 -d \" \"'",
+                             g_get_user_name ());
+#else
+  command = g_strdup_printf ("sh -c 'getent passwd %s | head -n1 | cut -f 7 -d :'",
+                             g_get_user_name ());
+#endif
+
+  if (!g_shell_parse_argv (command, NULL, &argv, &error))
+    {
+      g_warning ("Failed to parse command into argv: %s",
+                 error ? error->message : "unknown error");
+      return;
+    }
+
+  /*
+   * We don't use the runtime shell here, because we want to know
+   * what the host thinks the user shell should be.
+   */
+  launcher = ide_subprocess_launcher_new (G_SUBPROCESS_FLAGS_STDOUT_PIPE);
+
+  ide_subprocess_launcher_set_run_on_host (launcher, TRUE);
+  ide_subprocess_launcher_set_clear_env (launcher, FALSE);
+  ide_subprocess_launcher_set_cwd (launcher, g_get_home_dir ());
+  ide_subprocess_launcher_push_args (launcher, (const gchar * const *)argv);
+
+  if (!(subprocess = ide_subprocess_launcher_spawn (launcher, NULL, &error)))
+    {
+      g_warning ("Failed to spawn getent: %s", error->message);
+      return;
+    }
+
+  ide_subprocess_communicate_utf8_async (subprocess,
+                                         NULL,
+                                         NULL,
+                                         ide_guess_shell_communicate_cb,
+                                         (gpointer)"SHELL");
+}
+
+void
+_ide_guess_user_path (void)
+{
+  g_autoptr(IdeSubprocessLauncher) launcher = NULL;
+  g_autoptr(IdeSubprocess) subprocess = NULL;
+  g_autofree gchar *command = NULL;
+  g_autoptr(GError) error = NULL;
+  g_auto(GStrv) argv = NULL;
+
+  command = g_strdup_printf ("sh --login -c 'echo $PATH'");
+
+  if (!g_shell_parse_argv (command, NULL, &argv, &error))
+    {
+      g_warning ("Failed to parse command into argv: %s",
+                 error ? error->message : "unknown error");
+      return;
+    }
+
+  launcher = ide_subprocess_launcher_new (G_SUBPROCESS_FLAGS_STDOUT_PIPE);
+  ide_subprocess_launcher_set_run_on_host (launcher, TRUE);
+  ide_subprocess_launcher_set_clear_env (launcher, FALSE);
+  ide_subprocess_launcher_set_cwd (launcher, g_get_home_dir ());
+  ide_subprocess_launcher_push_args (launcher, (const gchar * const *)argv);
+
+  if (!(subprocess = ide_subprocess_launcher_spawn (launcher, NULL, &error)))
+    {
+      g_warning ("Failed to spawn getent: %s", error->message);
+      return;
+    }
+
+  ide_subprocess_communicate_utf8_async (subprocess,
+                                         NULL,
+                                         NULL,
+                                         ide_guess_shell_communicate_cb,
+                                         (gpointer)"PATH");
+}
+
+/**
+ * ide_get_user_shell:
+ *
+ * Gets the user preferred shell on the host.
+ *
+ * If the background shell discovery has not yet finished due to
+ * slow or misconfigured getent on the host, this will provide a
+ * sensible fallback.
+ *
+ * Returns: (not nullable): a shell such as "/bin/sh"
+ */
+const gchar *
+ide_get_user_shell (void)
+{
+  return user_shell;
+}
+
+/**
+ * ide_get_user_default_path:
+ *
+ * Gets the default `$PATH` on the system for the user on the host.
+ *
+ * This value is sniffed during startup and will default to `SAFE_PATH`
+ * configured when building Builder until that value has been discovered.
+ *
+ * Returns: (not nullable): a string such as "/bin:/usr/bin"
+ */
+const char *
+ide_get_user_default_path (void)
+{
+  return user_default_path;
+}
diff --git a/src/libide/io/ide-shell.h b/src/libide/io/ide-shell.h
index ac086bae5..d2124f3e8 100644
--- a/src/libide/io/ide-shell.h
+++ b/src/libide/io/ide-shell.h
@@ -24,9 +24,13 @@
 
 G_BEGIN_DECLS
 
-IDE_AVAILABLE_IN_42
-gboolean ide_shell_supports_dash_c     (const char *shell);
-IDE_AVAILABLE_IN_42
-gboolean ide_shell_supports_dash_login (const char *shell);
+IDE_AVAILABLE_IN_ALL
+gboolean    ide_shell_supports_dash_c     (const char *shell);
+IDE_AVAILABLE_IN_ALL
+gboolean    ide_shell_supports_dash_login (const char *shell);
+IDE_AVAILABLE_IN_ALL
+const char *ide_get_user_shell            (void);
+IDE_AVAILABLE_IN_ALL
+const char *ide_get_user_default_path     (void);
 
 G_END_DECLS
diff --git a/src/libide/io/meson.build b/src/libide/io/meson.build
index 7fa64065b..8dcddbe89 100644
--- a/src/libide/io/meson.build
+++ b/src/libide/io/meson.build
@@ -21,6 +21,7 @@ libide_io_public_headers = [
 
 libide_io_private_headers = [
   'ide-gfile-private.h',
+  'ide-shell-private.h',
 ]
 
 install_headers(libide_io_public_headers, subdir: libide_io_header_subdir)