How can I compile my C program with the polkit library? - c

Question

Today, I tried to use polkit - an application-level toolkit for defining and handling the policy that allows unprivileged processes to speak to privileged processes. In order to understand it better, I tried to download this code:
#include <polkit/polkit.h>
static gboolean
on_tensec_timeout (gpointer user_data)
{
GMainLoop *loop = user_data;
g_print ("Ten seconds has passed. Now exiting.\n");
g_main_loop_quit (loop);
return FALSE;
}
static void
check_authorization_cb (PolkitAuthority *authority,
GAsyncResult *res,
gpointer user_data)
{
GMainLoop *loop = user_data;
PolkitAuthorizationResult *result;
GError *error;
error = NULL;
result = polkit_authority_check_authorization_finish (authority, res, &error);
if (error != NULL)
{
g_print ("Error checking authorization: %s\n", error->message);
g_error_free (error);
}
else
{
const gchar *result_str;
if (polkit_authorization_result_get_is_authorized (result))
{
result_str = "authorized";
}
else if (polkit_authorization_result_get_is_challenge (result))
{
result_str = "challenge";
}
else
{
result_str = "not authorized";
}
g_print ("Authorization result: %s\n", result_str);
}
g_print ("Authorization check has been cancelled and the dialog should now be hidden.\n"
"This process will exit in ten seconds.\n");
g_timeout_add (10000, on_tensec_timeout, loop);
}
static gboolean
do_cancel (GCancellable *cancellable)
{
g_print ("Timer has expired; cancelling authorization check\n");
g_cancellable_cancel (cancellable);
return FALSE;
}
int
main (int argc, char *argv[])
{
pid_t parent_pid;
const gchar *action_id;
GMainLoop *loop;
PolkitSubject *subject;
PolkitAuthority *authority;
GCancellable *cancellable;
g_type_init ();
if (argc != 2)
{
g_printerr ("usage: %s <action_id>\n", argv[0]);
return 1;
}
action_id = argv[1];
loop = g_main_loop_new (NULL, FALSE);
authority = polkit_authority_get_sync (NULL, NULL);
/* Typically mechanisms will use a PolkitSystemBusName since most
* clients communicate with the mechanism via D-Bus. However for
* this simple example we use the process id of the calling process.
*
* Note that if the parent was reaped we have to be careful not to
* check if init(1) is authorized (it always is).
*/
parent_pid = getppid ();
if (parent_pid == 1)
{
g_printerr ("Parent process was reaped by init(1)\n");
return 1;
}
subject = polkit_unix_process_new (parent_pid);
cancellable = g_cancellable_new ();
g_print ("Will cancel authorization check in 10 seconds\n");
/* Set up a 10 second timer to cancel the check */
g_timeout_add (10 * 1000,
(GSourceFunc) do_cancel,
cancellable);
polkit_authority_check_authorization (authority,
subject,
action_id,
NULL, /* PolkitDetails */
POLKIT_CHECK_AUTHORIZATION_FLAGS_ALLOW_USER_INTERACTION,
cancellable,
(GAsyncReadyCallback) check_authorization_cb,
loop);
g_main_loop_run (loop);
g_object_unref (authority);
g_object_unref (subject);
g_object_unref (cancellable);
g_main_loop_unref (loop);
return 0;
}
But when I tried to compile it with gcc, I received this output:
ciao.c:35:27: fatal error: polkit/polkit.h: File o directory non esistente
compilation terminated.

Answer 1

The path polkit/polkit.h is not in the system include path. Make sure you've downloaded and installed PolKit so that the headers and libraries are available.

Answer 2

I solved my problem adding this
pkg-config --cflags glib-2.0 polkit-gobject-1
and this
pkg-config --libs glib-2.0 polkit-gobject-1
to gcc compilation's command in this way
gcc `pkg-config --cflags glib-2.0 polkit-gobject-1` -o polkit PolicyKit/example.c `pkg-config --libs glib-2.0`