利用套接字搭建简易tcp服务器,完成小写转大写的操作(单进程版)
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <error.h>
#include <ctype.h>
#include <arpa/inet.h>
typedef struct sockaddr_in sockaddr_in;
typedef struct sockaddr sockaddr;
#define IP "192.168.43.150"
#define PORT 6666
int main()
{
int fd;
sockaddr_in addr;
sockaddr_in clie;
//创建套接字
fd = socket(AF_INET,SOCK_STREAM,0);
if(fd <0)
{
perror("socket");
return 0;
}
addr.sin_family = AF_INET;
addr.sin_port = htons(PORT);
char* ip = IP;
inet_pton(AF_INET,ip, &addr.sin_addr.s_addr);
//绑定端口号
int b = bind(fd,(sockaddr*)&addr,sizeof(sockaddr_in));
if(b<0)
{
perror("bind");
return 0;
}
//监听 设置连接数
int l = listen(fd,32);
if(l<0)
{
perror("listen");
return 0;
}
//接收连接
socklen_t len;
len = sizeof(clie);
int cfd = accept(fd,(sockaddr*)&clie,&len);
if(cfd <0)
{
perror("accept");
return 0;
}
//数据处理
while(1)
{
char buff[1024];
int n = read(cfd,buff,sizeof(buff));
int i=0;
for(i=0;i<n;++i)
{
buff[i] = toupper(buff[i]);
}
write(cfd,buff,n);
}
close(fd);
close(cfd);
}
