linux socket编程入门.docx

intsocket(intdomain,inttype,intprotocol);
intbind(intsockfd,structsockaddr*my_addr,intaddrlen);
intconnect(intsockfd,structsockaddr*serv_addr,intaddrlen);
intlisten(intsockfd，intbacklog);
intaccept(intsockfd,void*addr,int*addrlen);
intsend(intsockfd,constvoid*msg,intlen,intflags);
intrecv(intsockfd,void*buf,intlen,unsignedintflags);
close(sockfd);
intshutdown(intsockfd,inthow);
intselect(intnumfds,fd_set*readfds,fd_set*writefds，fd_set*exceptfds,structtimeval*timeout);

structsockaddr{
unsignedshortsa_family;/*地址族，AF_xxx*/
charsa_data[14];/*14字节的协议地址*/
};

structsockaddr_in{
shortintsin_family;/*地址族*/
unsignedshortintsin_port;/*端口号*/
structin_addrsin_addr;/*IP地址*/
unsignedcharsin_zero[8];/*填充0以保持与structsockaddr同样大小*/
};

structtimeval{
inttv_sec;/*seconds*/
inttv_usec;/*microseconds*/
};

typedefstruct{
/*XPG4.2requiresthismembername.Otherwiseavoidthename
fromtheglobalnamespace.*/
#ifdef__USE_XOPEN
__fd_maskfds_bits[__FD_SETSIZE/__NFDBITS];
#define__FDS_BITS(set)((set)->fds_bits)
#else
__fd_mask__fds_bits[__FD_SETSIZE/__NFDBITS];
#define__FDS_BITS(set)((set)->__fds_bits)
#endif
}fd_set;

一个聊天程序
服务器代码
#include<stdlib.h>
#include<stdio.h>
#include<netdb.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<string.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<unistd.h>
#include<fcntl.h>

#defineMAXDATASIZE256

#defineSERVPORT4444/*服务器监听端口号*/
#defineBACKLOG1/*最大同时连接请求数*/
#defineSTDIN0/*标准输入文件描述符*/

intmain(void)
{
FILE*fp;/*定义文件类型指针fp*/
intsockfd,client_fd;/*监听socket.sock_fd,数据传输socket.new_fd*/
intsin_size;
structsockaddr_inmy_addr,remote_addr;/*本机地址信息,客户地址信息*/
charbuf[256];/*用于聊天的缓冲区*/

charbuff[256];/*用于输入用户名的缓冲区*/
charsend_str[256];/*最多发出的字符不能超过256*/
intrecvbytes;
fd_setrfd_set,wfd_set,efd_set;/*被select()监视的读、写、异常处理的文件描述符集合*/
structtimevaltimeout;/*本次select的超时结束时间*/
intret;/*与client连接的结果*/

if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1){/*错误检测*/
perror("socket");
exit(1);
}
/*端填充sockaddr结构*/
bzero(&my_addr,sizeof(structsockaddr_in));
my_addr.sin_fam