请使用c语言写一个http服务器

好的，以下是一个简单的C语言HTTP服务器的示例代码：

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

#define PORT 8080
#define BUFFER_SIZE 1024

int main(int argc, char const *argv[]) {
    int server_fd, new_socket, valread;
    struct sockaddr_in address;
    int opt = 1;
    int addrlen = sizeof(address);
    char buffer[BUFFER_SIZE] = {0};
    char *response = "HTTP/1.1 200 OK\nContent-Type: text/plain\nContent-Length: 12\n\nHello world!";

    // Create socket file descriptor
    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
        perror("socket failed");
        exit(EXIT_FAILURE);
    }

    // Set socket options
    if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {
        perror("setsockopt failed");
        exit(EXIT_FAILURE);
    }

    // Bind socket to port
    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = htons(PORT);
    if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {
        perror("bind failed");
        exit(EXIT_FAILURE);
    }

    // Listen for incoming connections
    if (listen(server_fd, 3) < 0) {
        perror("listen failed");
        exit(EXIT_FAILURE);
    }

    // Accept incoming connection
    if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t*)&addrlen)) < 0) {
        perror("accept failed");
        exit(EXIT_FAILURE);
    }

    // Read incoming request
    valread = read(new_socket, buffer, BUFFER_SIZE);
    printf("%s\n", buffer);

    // Send response
    send(new_socket, response, strlen(response), 0);
    printf("Hello message sent\n");

    // Close sockets
    close(new_socket);
    close(server_fd);

    return 0;
}

这个HTTP服务器使用了基本的套接字编程技术，监听端口8080，当有新的客户端连接时，读取客户端发送的请求，然后返回一个简单的响应消息。请注意，这个示例代码并不适用于生产环境，只是用于演示HTTP服务器的基本工作原理。