# Basic registration
[Tutorials:]

This program is a _very_ simple usage example of liblinphone. Desmonstrating how to initiate a SIP registration from a sip uri identity passed from the command line. first argument must be like sip:jehan@sip.linphone.org , second must be password .
ex registration sip:jehan@sip.linphone.org secret
Registration is cleared on SIGINT

    /*
    linphone
    Copyright (C) 2010  Belledonne Communications SARL

    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 2
    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, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
    */

    #ifdef IN_LINPHONE
    #include "linphonecore.h"
    #else
    #include "linphone/linphonecore.h"
    #endif

    #include <signal.h>

    static bool_t running=TRUE;

    static void stop(int signum){
            running=FALSE;
    }

    static void registration_state_changed(struct _LinphoneCore *lc, LinphoneProxyConfig *cfg, LinphoneRegistrationState cstate, const char *message){
                    printf("New registration state %s for user id [%s] at proxy [%s]\n"
                                    ,linphone_registration_state_to_string(cstate)
                                    ,linphone_proxy_config_get_identity(cfg)
                                    ,linphone_proxy_config_get_addr(cfg));
    }

    LinphoneCore *lc;
    int main(int argc, char *argv[]){
            LinphoneCoreVTable vtable={0};

            char* identity=NULL;
            char* password=NULL;

            /* takes   sip uri  identity from the command line arguments */
            if (argc>1){
                    identity=argv[1];
            }

            /* takes   password from the command line arguments */
            if (argc>2){
                    password=argv[2];
            }

            signal(SIGINT,stop);

    #ifdef DEBUG
            linphone_core_enable_logs(NULL); /*enable liblinphone logs.*/
    #endif
            /*
             Fill the LinphoneCoreVTable with application callbacks.
             All are optional. Here we only use the registration_state_changed callbacks
             in order to get notifications about the progress of the registration.
             */
            vtable.registration_state_changed=registration_state_changed;

            /*
             Instanciate a LinphoneCore object given the LinphoneCoreVTable
            */
            lc=linphone_core_new(&vtable,NULL,NULL,NULL);

            LinphoneProxyConfig* proxy_cfg;
            /*create proxy config*/
            proxy_cfg = linphone_proxy_config_new();
            /*parse identity*/
            LinphoneAddress *from = linphone_address_new(identity);
            if (from==NULL){
                    printf("%s not a valid sip uri, must be like sip:toto@sip.linphone.org \n",identity);
                    goto end;
            }
                    LinphoneAuthInfo *info;
                    if (password!=NULL){
                            info=linphone_auth_info_new(linphone_address_get_username(from),NULL,password,NULL,NULL); /*create authentication structure from identity*/
                            linphone_core_add_auth_info(lc,info); /*add authentication info to LinphoneCore*/
                    }

                    // configure proxy entries
                    linphone_proxy_config_set_identity(proxy_cfg,identity); /*set identity with user name and domain*/
                    const char* server_addr = linphone_address_get_domain(from); /*extract domain address from identity*/
                    linphone_proxy_config_set_server_addr(proxy_cfg,server_addr); /* we assume domain = proxy server address*/
                    linphone_proxy_config_enable_register(proxy_cfg,TRUE); /*activate registration for this proxy config*/
                    linphone_address_destroy(from); /*release resource*/

                    linphone_core_add_proxy_config(lc,proxy_cfg); /*add proxy config to linphone core*/
                    linphone_core_set_default_proxy(lc,proxy_cfg); /*set to default proxy*/

            /* main loop for receiving notifications and doing background linphonecore work: */
            while(running){
                    linphone_core_iterate(lc); /* first iterate initiates registration */
                    ms_usleep(50000);
            }

            linphone_core_get_default_proxy(lc,&proxy_cfg); /* get default proxy config*/
            linphone_proxy_config_edit(proxy_cfg); /*start editing proxy configuration*/
            linphone_proxy_config_enable_register(proxy_cfg,FALSE); /*de-activate registration for this proxy config*/
            linphone_proxy_config_done(proxy_cfg); /*initiate REGISTER with expire = 0*/

            while(linphone_proxy_config_get_state(proxy_cfg) !=  LinphoneRegistrationCleared){
                    linphone_core_iterate(lc); /*to make sure we receive call backs before shutting down*/
                    ms_usleep(50000);
            }

    end:
            printf("Shutting down...\n");
            linphone_core_destroy(lc);
            printf("Exited\n");
            return 0;
    }