用c语言
时间: 2024-02-24 16:57:41 浏览: 13
使用C语言编写套接字程序可以使用Socket API,以下是一个简单的示例代码:
服务器端:
```c
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <unistd.h>
int main()
{
int sockfd, newsockfd, portno, clilen;
char buffer[256];
struct sockaddr_in serv_addr, cli_addr;
int n;
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0)
{
perror("ERROR opening socket");
exit(1);
}
bzero((char *)&serv_addr, sizeof(serv_addr));
portno = 5001;
serv_addr.sin_family = AF_INET;
serv_addr.sin_addr.s_addr = INADDR_ANY;
serv_addr.sin_port = htons(portno);
if (bind(sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0)
{
perror("ERROR on binding");
exit(1);
}
listen(sockfd, 5);
clilen = sizeof(cli_addr);
newsockfd = accept(sockfd, (struct sockaddr *)&cli_addr, &clilen);
if (newsockfd < 0)
{
perror("ERROR on accept");
exit(1);
}
bzero(buffer, 256);
n = read(newsockfd, buffer, 255);
if (n < 0)
{
perror("ERROR reading from socket");
exit(1);
}
printf("Here is the message: %s\n", buffer);
n = write(newsockfd, "I got your message", 18);
if (n < 0)
{
perror("ERROR writing to socket");
exit(1);
}
close(newsockfd);
close(sockfd);
return 0;
}
```
客户端:
```c
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <string.h>
#include <unistd.h>
int main()
{
int sockfd, portno, n;
struct sockaddr_in serv_addr;
struct hostent *server;
char buffer[256];
portno = 5001;
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0)
{
perror("ERROR opening socket");
exit(1);
}
server = gethostbyname("localhost");
if (server == NULL)
{
fprintf(stderr, "ERROR, no such host\n");
exit(0);
}
bzero((char *)&serv_addr, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
bcopy((char *)server->h_addr, (char *)&serv_addr.sin_addr.s_addr, server->h_length);
serv_addr.sin_port = htons(portno);
if (connect(sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0)
{
perror("ERROR connecting");
exit(1);
}
printf("Please enter the message: ");
bzero(buffer, 256);
fgets(buffer, 255, stdin);
n = write(sockfd, buffer, strlen(buffer));
if (n < 0)
{
perror("ERROR writing to socket");
exit(1);
}
bzero(buffer, 256);
n = read(sockfd, buffer, 255);
if (n < 0)
{
perror("ERROR reading from socket");
exit(1);
}
printf("%s\n", buffer);
close(sockfd);
return 0;
}
```
以上代码中,服务器端在端口号5001上侦听客户端的连接请求,客户端连接到服务器的IP地址和端口号,发送一条消息给服务器,服务器接收到消息后回复一条确认消息,然后关闭连接。