简单实现linux聊天室程序

花了很长时间用来练习掌握linux上socket的一个聊天室程序，可以实现的哦。
具体代码如下

代码一：

#ifndef _I_H #define _I_H #include <math.h>#include <stdio.h>#include <sys/socket.h>#include <arpa/inet.h>#include <netinet/in.h>#include <unistd.h>#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <stdlib.h>#include <errno.h>#include <string.h>#include <inttypes.h>#include <time.h>#include <sys/ioctl.h> #include <net/if.h>#include <signal.h>#include <ncurses.h>#include <math.h> #define SEVR_IP   "127.0.0.1"#define SEVR_PORT  8081#define CNTNT_LEN  150#define MSG_LEN   sizeof(struct msg)#define ADDR_LEN  sizeof(struct sockaddr)#define USR_LEN   sizeof(struct user)#define PRT_LEN   8#define HSTR_LEN  sizeof(struct chat_history) /* declare Global variables */int mainfd;/* used as chat histroy file handle*/int sockfd;/* used as socket local handle */int count;struct sockaddr_in server; /* msg is used for communicating message */struct msg{  int flag; /* flag meaning:1,ordinary; 2,log msg; 3,reg msg, other,file*/  int id_from;  int id_to;  char content[CNTNT_LEN];  char append[10]; }; /* user is used information list */struct user{  int id;  char name[10];  char password[10];  char *p_chatlog;  struct sockaddr user_addr; };/* chat_history used for reading chat history */struct chat_history{  char content[CNTNT_LEN];  char time[25];  int to;  int from;  int count;}; /* i_functions below is funtions needed by both client and sever */extern int i_saveto_chat(struct msg *pmsg); int i_clean_stdin (){  while ('/n' == getchar())  {    continue;  }   return(0);} int i_print(char *pmsg, int size){  int i = 1;   for (i; i<= size; i++)  {    if (*pmsg != '/n')    {      printf("%c", *pmsg);      pmsg ++;    }    else    {      return(0);    }  }   return(0);}int i_input(char *p_input){  char c = '/0';  int i;    for (i = 0; i < CNTNT_LEN; i++)  {    p_input[i] = getchar();    if (p_input[i] =='/n')    {      return(0);       }      }   printf("you have input long enough!/n");  return(0);}int i_socket(int domain, int type, int protocol){  int fd;    if ((fd = socket(domain, type, protocol)) == -1)  {    perror("creat socket error:");    exit(1);  }     return(fd); } int i_bind(int fd, const struct sockaddr *addr, int namelen){  if (-1 == bind(fd, addr, namelen))  {    perror("i_bind error:");    exit(1);  }     return (0);} int i_recvfrom(int fd, void *buf, size_t len, int flags,     struct sockaddr *addr, int *size){    if (-1 == recvfrom(fd, buf, len, flags, addr, size))  {    perror("i_recvfrom error:");    exit(1);    }     return(0);} int i_sendto(int fd, void *buf, size_t len, int flags,    struct sockaddr *addr, int size){  if (-1 == sendto(fd, buf, len, flags, addr, size))  {    perror("i_sendto error");    exit(1);    }     return (0);} int i_open(const char *pathname, int flags){  int fd;  if ((fd = open(pathname, flags)) == -1)  {    perror("open_failed");    exit(1);  }     return (fd);}int i_read(int fd, void *msg, int len){  if(-1 == read(fd, msg, len))  {    perror("i_read error");    exit(1);  }  return(0);}int i_write(int fd, void *msg, int len){  if (-1 == write(fd, msg, len))  {    perror("i_write error");    exit(0);  }  return(0);} /* init a socket,file and server addr */int i_init(){  mainfd = i_open("./chat_log", O_RDWR|O_CREAT);  sockfd = i_socket(AF_INET, SOCK_DGRAM, 0);   /* initialize server address */  bzero(&server, sizeof(server));  server.sin_family = AF_INET;  inet_pton(AF_INET, "127.0.0.1", &server.sin_addr);  server.sin_port = htons(SEVR_PORT);   perror("init");     return (0);} char *i_get_time(){  time_t time_now;  time(&time_now);   return(ctime(&time_now));}int i_lseek(int fd, off_t size, int position){  if (-1 == lseek(fd, size, position))  {    perror("seek error");    exit(1);  }  return(0);}int i_saveto_chat(struct msg *pmsg){    struct chat_history hstr;    bzero(&hstr, HSTR_LEN);  count = count + 1;  hstr.count =count;  hstr.from = pmsg->id_from;  hstr.to = pmsg->id_to;  strncpy(hstr.content, pmsg->content, CNTNT_LEN);  strncpy(hstr.time, i_get_time(), 25);   i_lseek(mainfd, 0, SEEK_END);   i_write(mainfd, &hstr, HSTR_LEN);   return(0);} int i_print_history(int len, int i){  struct chat_history chat_reader;  int j;  int position;     bzero(&chat_reader, HSTR_LEN);  if (i != 0)  {    position = len*i*HSTR_LEN;    i_lseek(mainfd, position, SEEK_END);  }  else  {    position = len*i*HSTR_LEN;     i_lseek(mainfd, HSTR_LEN, SEEK_SET);  }       for (j = 1; j <= len; j++)  {         i_read(mainfd, &chat_reader, HSTR_LEN);    printf("/n#item%d:id%dto id%d /n", j,      chat_reader.from, chat_reader.to);    i_print(chat_reader.content, CNTNT_LEN);    printf("/n Time:%s/n", chat_reader.time);  }   return(0);} #endif