写一段C语言网络发送代码

以下是一个简单的C语言网络发送代码示例：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>

int main(int argc, char *argv[]) {
    int sockfd, portno, n;
    struct sockaddr_in serv_addr;
    struct hostent *server;

    char buffer[256];
    if (argc < 3) {
        fprintf(stderr,"usage %s hostname port\n", argv[0]);
        exit(0);
    }

    portno = atoi(argv[2]);
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) {
        perror("ERROR opening socket");
        exit(1);
    }

    server = gethostbyname(argv[1]);
    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;
}

该代码使用TCP套接字连接到指定的主机和端口号，并将用户输入的消息发送到服务器。服务器将给出响应，该响应将由客户端所读取并输出到屏幕上。