/* Rotina1 - emissor
Esta rotina recebe uma linha do teclado e envia-a para uma outra */
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
main(void)
{
struct sockaddr_in me, target;
int sock, addrlen=sizeof(me);
char linha[81];
sock=socket(AF_INET,SOCK_DGRAM, 0);
bzero((char*)&me, addrlen);
me.sin_family=AF_INET;
me.sin_addr.s_addr=htonl(INADDR_ANY);
me.sin_port=htons(0);
bzero((char*)&target, sizeof(target));
target.sin_family=AF_INET;
target.sin_addr.s_addr=inet_addr("193.136.62.26"); /* ideafix */
target.sin_port=htons(8450);
bind(sock,(struct sockaddr*)&me, addrlen);
do
	{
	gets(linha);
    sendto(sock, linha, 81, 0, (struct sockaddr*)&target, sizeof(target));
	}
while(strcmp(linha, "fim"));
close(sock);
}



/* Rotina2 - intermédio
Esta rotina recebe uma informação da Rotina1, converte-a para maiúsculas, e
envia-a para a Rotina3 */
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
main(void)
{
struct sockaddr_in from, me, target;
int sock, addrlen=sizeof(me), i;
char linha[81];
sock=socket(AF_INET,SOCK_DGRAM, 0);
bzero((char*)&me, addrlen);
me.sin_family=AF_INET;
me.sin_addr.s_addr=htonl(INADDR_ANY);
me.sin_port=htons(8450);
bzero((char*)&target, sizeof(target));
target.sin_family=AF_INET;
target.sin_addr.s_addr=inet_addr("193.136.62.24"); /* asterix */
target.sin_port=htons(8450);
bind(sock,(struct sockaddr*)&me, addrlen);
do
	{
	recvfrom(sock, linha, 81, 0, (struct sockaddr*)&from, &addrlen);
        i=0;
        while (linha[i] != '\0')
        	{linha[i] = toupper(linha[i]);
                i++;}
        puts(linha);
        sendto(sock, linha, 81, 0, (struct sockaddr*)&target, sizeof(target));
	}
while(strcmp(linha, "FIM"));
close(sock);
}



/* Rotina3 - receptor
Esta rotina recebe uma informação da Rotina2 e converte-a para minúsculas */
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
main(void)
{
struct sockaddr_in me, from;
int sock=socket(AF_INET,SOCK_DGRAM,0);
int addrlen=sizeof(from), i;
char linha[81];
bzero((char*)&me, sizeof(me));
me.sin_family=AF_INET;
me.sin_addr.s_addr=htonl(INADDR_ANY);
me.sin_port=htons(8450);
bind(sock,(struct sockaddr*)&me, sizeof(me));
do
	{
        recvfrom(sock, linha, 81, 0, (struct sockaddr*)&from, &addrlen);
        i=0;
        while (linha[i] != '\0')
        	{linha[i] = tolower(linha[i]);
                i++;}
        puts(linha);
	}
while(strcmp(linha, "fim"));
close(sock);
}