Programmation reseau:sockets

Bonjour, au fait j'ai un petit probleme, je commence la programmation reseau et je dois envoyer un message grace aux sockets sur le reseau local ou sur autre terminal ouvert.Et je sais pas vraiment comment debugger les erreurs.
La transmission se fait hors connexion pour le moment(UDP).

Voici le code qui transmet et je sais pas vraiment si je dois mettre le code qui recoit pour vous :


#include <sys/socket.h>
#include<sys/un.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <arpa/inet.h>
#define UDP_port 8000
#define HOST_addr "191.8.220.12"



int main (void) {

int sdc;
int sd;
int lgr_add_expedi;
lgr_add_expedi=16;
int lgr_add_desti;
lgr_add_desti=16;
sdc=0;
struct sockaddr_in sa,server_s;

sd=socket(AF_INET,SOCK_DGRAM,0);

char message[256];
while( sdc<99){ message[sdc]='a';
sdc++;}




bzero((char *)&server_s,sizeof(server_s));
server_s.sin_family=AF_INET;
server_s.sin_addr.s_addr=htonl(0);
server_s.sin_port=htons(6666);

if(bind(sd,(struct sockaddr *)&server_s,sizeof(server_s))<0)

{
printf("bind:can't connect local adress");

exit(1);

}

sendto(sd, message,100,0,(struct sockaddr *)&server_s,lgr_add_desti);

recvfrom(sd,message,sizeof(message),0,(struct sockaddr *)&sa,&lgr_add_expedi);
printf(" message recu %s\n" ,message);

}




et voici les erreurs :
Sorry, command-not-found has crashed! Please file a bug report at:
https://bugs.launchpad.net/ubuntu/+source/command-not-found
Please include the following information with the report:
unsupported locale setting
Traceback (most recent call last):
File "/usr/lib/command-not-found", line 19, in <module>
parser = OptionParser(version = __version__, usage=_("%prog [options] <command-name>"))
File "/usr/lib/python2.5/gettext.py", line 584, in lgettext
return ldgettext(_current_domain, message)
File "/usr/lib/python2.5/gettext.py", line 556, in ldgettext
return t.lgettext(message)
File "/usr/lib/python2.5/gettext.py", line 366, in lgettext
return tmsg.encode(locale.getpreferredencoding())
File "/usr/lib/python2.5/locale.py", line 514, in getpreferredencoding
setlocale(LC_CTYPE, "")
File "/usr/lib/python2.5/locale.py", line 478, in setlocale
return _setlocale(category, locale)
Error: unsupported locale setting
Python version: 2.5.2 final 0
bash: envoi : commande introuvable

Je vous remercie d'avance