Old snippet from the beginning.

ircbot.c

#include <netdb.h>
#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>

#define DSTADDR "darklite.be.eu.SwiftIRC.net"
#define DSTPORT 6667

#define BUFF_SIZE 512

int main(int argc, char * argv[])
{

          struct hostent * canonical;
          canonical = gethostbyname(DSTADDR);

          if (!canonical)
                  {
                            printf("Unknown host: %s\r\n", DSTADDR);
                            return 1;
                          }

          int fd;
          fd = socket(AF_INET, SOCK_STREAM, 0);

          if (fd < 0)
                  {
                            printf("Error creating socket.\r\n");
                            return 1;
                          }

          struct sockaddr_in client;

          memset(&client, 0, sizeof client);

          client.sin_family = AF_INET;
          client.sin_port = htons(DSTPORT);

          memcpy(&client.sin_addr, canonical->h_addr, canonical->h_length);

          int eid;
          eid = connect(fd, (struct sockaddr *) &client, sizeof client);

          if (eid < 0)
                  {
                            printf("Error connecting socket.\r\n");
                            return 1;
                          }

          char buff[BUFF_SIZE];

          memset(buff, 0, sizeof buff);

          sprintf(buff, "NICK %s\r\n", "H2O");
          send(fd, buff, strlen(buff), 0);
          memset(buff, 0, sizeof buff);
          
          sprintf(buff, "USER %s \"\" \"\" :%s\r\n", "svs", "c");
          send(fd, buff, strlen(buff), 0);
          memset(buff, 0, sizeof buff);
        
          char pong[BUFF_SIZE];
          
          while (recv(fd, buff, sizeof buff, 0) > 0) 
                  {
                            if (sscanf(buff, "PING :%s", pong) > 0)
                                    {
                                              sprintf(buff, "PONG :%s\r\n", pong);
                                              send(fd, buff, strlen(buff), 0);
                                            }
                            printf("-> %s\r\n", buff);
                            memset(buff, 0, sizeof buff);
                          }
        
          close(fd);
          return 0;
}