鉴于TCP之简单回传（一） 中所出现的问题，本博文所要采取的一种方法是：
客户端：先向服务器传送一个 int32_t 大小的数据，表示随后所要发送数据的真实长度； 服务器：先接收一个int32_t 大小的数据，再接收真实的数据；
本程序中所用到的函数都可以在 TCP之函数封装 中找到；
server服务器端具体实现：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define ERR_EXIT(m) do { perror(m); exit(EXIT_FAILURE); }while(0)
void do_server(int fd);
int main(int argc, const char *argv[])
{
//socket
int listenfd = socket(AF_INET, SOCK_STREAM, 0 );
if( -1 == listenfd)
ERR_EXIT("socket");
//地址复用
int on = 1;
if(setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof on) < 0)
ERR_EXIT("setsockopt");
//bind
struct sockaddr_in addr;
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(8888); //主机字节序转化为网络字节序
addr.sin_addr.s_addr = inet_addr("127.0.0.1");//点分十进制转化成网络字节序
if( -1 == bind( listenfd, (struct sockaddr*)&addr, sizeof(addr)))
ERR_EXIT("bind");
//listen
if( -1 == listen(listenfd,SOMAXCONN ))
ERR_EXIT("listen");
//accept
int peerfd = accept(listenfd, NULL, NULL);//对方的IP&PORT
//read&write
do_server(peerfd);
//close
close(peerfd);
close(listenfd);
return 0;
}
void do_server(int fd)
{
char recvbuf[1024100] = {0};
int cnt =0;
while(1)
{
int32_t len = recv_int32(fd);//先接收一个表示真是长度的int型数据
int nread = readn(fd, recvbuf, len);//读取数据
if(nread == -1)//err
{
if(errno == EINTR)
continue;
ERR_EXIT("read");
}else if (nread == 0 || nread < len )//write close
{
printf("close...\n");
exit(EXIT_FAILURE);
}
// ok
printf("count = %d recv size = %d\n",++cnt, nread);
memset(recvbuf, 0, sizeof(recvbuf));
}
}
client客户端具体实现：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define ERR_EXIT(m) do { perror(m); exit(EXIT_FAILURE); }while(0)
void do_server(int fd);
int main(int argc, const char *argv[])
{
//socket
int peerfd = socket(AF_INET, SOCK_STREAM,0);
if( -1 == peerfd)
ERR_EXIT("socket");
//connect
struct sockaddr_in addr;
addr.sin_family = AF_INET;
addr.sin_port = htons(8888);
addr.sin_addr.s_addr = inet_addr("127.0.0.1");
if( -1 == connect(peerfd,(struct sockaddr*)&addr, sizeof(addr) ))
ERR_EXIT("connect");
//read&write
do_server(peerfd);
return 0;
}
void do_server(int fd)
{
#define SIZE 1024
char sendbuf[SIZE +1]= {0};
int i ;
for (i = 0; i < SIZE; i++)
{
sendbuf[i]= ‘a‘;
}
int cnt =0;
while(1)
{
int i;
for (i = 0; i < 10; i++)
{
send_int32(fd, SIZE);//先发送一个表示真实长度的int型数据
int nwrite =writen(fd, sendbuf, SIZE);//写数据
if( nwrite != SIZE)//err
ERR_EXIT("writen");
printf("cout = %d,write %d bytes\n",++cnt, SIZE);
}
nano_sleep(4.5);
}
}
测试结果：
./server count = 1 recv size = 1024 count = 2 recv size = 1024 count = 3 recv size = 1024 count = 4 recv size = 1024 count = 5 recv size = 1024 count = 6 recv size = 1024 count = 7 recv size = 1024 count = 8 recv size = 1024 count = 9 recv size = 1024 count = 10 recv size = 1024 count = 11 recv size = 1024 count = 12 recv size = 1024 count = 13 recv size = 1024 count = 14 recv size = 1024 count = 15 recv size = 1024 count = 16 recv size = 1024 count = 17 recv size = 1024 count = 18 recv size = 1024 count = 19 recv size = 1024 count = 20 recv size = 1024
./client cout = 1,write 1024 bytes cout = 2,write 1024 bytes cout = 3,write 1024 bytes cout = 4,write 1024 bytes cout = 5,write 1024 bytes cout = 6,write 1024 bytes cout = 7,write 1024 bytes cout = 8,write 1024 bytes cout = 9,write 1024 bytes cout = 10,write 1024 bytes cout = 11,write 1024 bytes cout = 12,write 1024 bytes cout = 13,write 1024 bytes cout = 14,write 1024 bytes cout = 15,write 1024 bytes cout = 16,write 1024 bytes cout = 17,write 1024 bytes cout = 18,write 1024 bytes cout = 19,write 1024 bytes cout = 20,write 1024 bytes
时间： 2024-10-12 19:10:47