c语言网络编程-标准步骤，真的很简单啊

server.c

复制代码 代码如下:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>

#define PORT 4444
#define BACKLOG 5

int main(int argc, char *argv[]) {
int sock_fd, new_fd;
struct sockaddr_in server_addr, client_addr;
int sin_size;
int nbytes;
int on = 1;
char buffer[1024];

if ((sock_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
perror("socket");
exit(1);
}

setsockopt(sock_fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));

memset(&server_addr, 0, sizeof(struct sockaddr_in));
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
server_addr.sin_port = htons(PORT);

if (bind(sock_fd, (struct sockaddr *)(&server_addr), sizeof(struct sockaddr)) == -1) {
perror("bind");
exit(1);
}

if (listen(sock_fd, BACKLOG) == -1) {
perror("listen");
exit(1);
}

printf("Server start... \n");

while (1) {
sin_size = sizeof(struct sockaddr_in);
if ((new_fd = accept(sock_fd, (struct sockaddr *)(&client_addr), &sin_size)) == -1) {
perror("accept");
exit(1);
}

printf("Server get connection from %s\n", inet_ntoa(client_addr.sin_addr));
if ((nbytes = read(new_fd, buffer, 1024)) == -1) {
perror("read");
exit(1);
}
buffer[nbytes] = '\0';
printf("Server received: %s\n", buffer);
close(new_fd);
}

return 0;
}

client.c

复制代码 代码如下:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>

#define PORT 4444

int main(int argc, char *argv[]) {
int sock_fd;
struct sockaddr_in server_addr;
struct hostent *host;
char buffer[1024];

if (argc < 2) {
perror("Need hostname");
exit(1);
}

if ((host = gethostbyname(argv[1])) == NULL) {
perror("gethostbyname");
exit(1);
}

if ((sock_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
perror("socket");
exit(1);
}

memset(&server_addr, 0, sizeof(struct sockaddr_in));
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(PORT);
server_addr.sin_addr = *((struct in_addr *)host->h_addr);

if (connect(sock_fd, (struct sockaddr *)(&server_addr), sizeof(struct sockaddr)) == -1) {
perror("connect");
exit(1);
}

printf("Please input something:\n");
fgets(buffer, 1024, stdin);
write(sock_fd, buffer, strlen(buffer));
close(sock_fd);

return 0;
}