dbus c program - send(with reply) and receive using method_call - dbus

Question

I'm new to D-Bus. I want a c program to send and receive data using the dbus_message_new_method_call function. I have tried the following programs from the link How to reply a D-Bus message but I'm getting error in the server.c side like "the name client.signal.Object was not provided by any .service files"
"server.c"
/* server.c */
#include <dbus/dbus.h>
#include <stdbool.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
static DBusHandlerResult
filter_func(DBusConnection *connection, DBusMessage *message, void *usr_data)
{
DBusMessage *reply;
dbus_bool_t handled = false;
char *word = NULL;
DBusError dberr;
dbus_error_init(&dberr);
dbus_message_get_args(message, &dberr, DBUS_TYPE_STRING, &word, DBUS_TYPE_INVALID);
printf("receive message: %s\n", word);
handled = true;
reply = dbus_message_new_method_return(message);
char * reply_content;
printf("\nEnter your Reply Msg : ");
scanf("%s",reply_content);
dbus_message_append_args(reply, DBUS_TYPE_STRING, &reply_content, DBUS_TYPE_INVALID);
dbus_connection_send(connection, reply, NULL);
dbus_connection_flush(connection);
dbus_message_unref(reply);
return (handled ? DBUS_HANDLER_RESULT_HANDLED : DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
}
int main(int argc, char *argv[])
{
DBusError dberr;
DBusConnection *dbconn;
dbus_error_init(&dberr);
dbconn = dbus_bus_get(DBUS_BUS_SESSION, &dberr);
if (!dbus_connection_add_filter(dbconn, filter_func, NULL, NULL))
{
return -1;
}
dbus_bus_add_match(dbconn, "type='method_call',interface='client.signal.Type'", &dberr);
while(dbus_connection_read_write_dispatch(dbconn, -1))
{
/* loop */
}
return 0;
}
here client.c
#include <dbus/dbus.h>
#include <stdbool.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
static DBusHandlerResult
filter_func(DBusConnection *connection, DBusMessage *message, void *usr_data)
{
dbus_bool_t handled = false;
char *word = NULL;
DBusError dberr;
dbus_error_init(&dberr);
dbus_message_get_args(message, &dberr, DBUS_TYPE_STRING, &word, DBUS_TYPE_INVALID);
printf("receive message %s\n", word);
handled = true;
return (handled ? DBUS_HANDLER_RESULT_HANDLED : DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
}
int db_send(DBusConnection *dbconn)
{
DBusMessage *dbmsg;
char *word = (char *)malloc(sizeof(char));
int i;
dbmsg = dbus_message_new_method_call("client.signal.Object","/client/signal/Object", "client.signal.Type", "Test");
scanf("%s", word);
if (!dbus_message_append_args(dbmsg, DBUS_TYPE_STRING, &word, DBUS_TYPE_INVALID))
{
return -1;
}
if (!dbus_connection_send(dbconn, dbmsg, NULL))
{
return -1;
}
dbus_connection_flush(dbconn);
printf("send message %s\n", word);
dbus_message_unref(dbmsg);
return 0;
}
int main(int argc, char *argv[])
{
DBusError dberr;
DBusConnection *dbconn;
dbus_error_init(&dberr);
dbconn = dbus_bus_get(DBUS_BUS_SESSION, &dberr);
if (!dbus_connection_add_filter(dbconn, filter_func, NULL, NULL))
{
return -1;
}
db_send(dbconn);
while(dbus_connection_read_write_dispatch(dbconn, -1))
{
db_send(dbconn);
}
dbus_connection_unref(dbconn);
return 0;
}
Please help me to fix.

Answer 1

Have a look here: http://www.freedesktop.org/wiki/IntroductionToDBus/
From what it looks like you need to write a file "*.service" that describes the service.
(Quoted from the website)
# (Lines starting with hash marks are comments)
# Fixed section header (do not change):
[D-BUS Service]
Names=com.bigmoneybank.Deposits;com.bigmoneybank.Withdrawals
Exec=/usr/local/bin/bankcounter
This is what I found within 5 minutes of Googleing.