linux 下基于socket 的B/S 架构web 服务器的构建

本设计设计的web服务器，根据服务机上指定的网页为默认网页，存储于本地，从浏览器中输入WEB服务器的地址，服务器响应，并发送默认网页给浏览器，由于默认网页中包含图片的内容，当浏览器读到该照片内容时，再向服务器发送照片请求，服务器响应请求，把浏览器所需要的内容打开，发送给浏览器。

 

本设计牵涉到 http协议，需根据协议信息头，分辨浏览器发送的请求内容，再做答复。答复中，也需要遵守http协议，先发送协议头，以便浏览器辨认识别。本文中采用了sscanf截取浏览器发送的http协议头中的文件信息。

#include <sys/types.h>
#include <sys/socket.h> // 包含套接字函数库
#include <stdio.h>
#include <netinet/in.h> // 包含AF_INET相关结构
#include <arpa/inet.h> // 包含AF_INET相关操作的函数
#include <unistd.h>
#include<string.h>
#include<stdlib.h>
#include<fcntl.h>
#include<sys/stat.h>
#include<dirent.h>


#define PORT 80
#define FILENAME "my.html"
#define SIZE 100

int main()
{



    int server_sockfd,client_sockfd;
    int server_len,client_len;

    struct sockaddr_in server_sockaddr,client_sockaddr;

    server_sockfd = socket(AF_INET,SOCK_STREAM, 0); // 定义套接字类型

    server_sockaddr.sin_family=AF_INET;
    server_sockaddr.sin_port=htons(PORT);
    server_sockaddr.sin_addr.s_addr=INADDR_ANY;

    server_len=sizeof(server_sockaddr);

    //允许重复使用本地地址和套接字绑定
    int j=1;
    setsockopt(server_sockfd,SOL_SOCKET,SO_REUSEADDR,&j,sizeof(j));

    //绑定端口
    if(bind(server_sockfd,(struct sockaddr *)&server_sockaddr,server_len)==-1)
    {
        perror("bind:");
        exit(1);
    }

    //监听端口
    if(listen(server_sockfd,5)==-1)
    {
        perror("listen:");
        exit(1);
    }
    printf("Listening...\n");


    unsigned char data_buf[2048];
    int i;

    struct stat statbuf;


    while(1)
    {
    if((client_sockfd=accept(server_sockfd,(struct sockaddr *)&client_sockaddr,&client_len))==-1)
        {
             perror("accept error:");
             exit(1);
        }

    printf("%s linked\n",inet_ntoa(client_sockaddr.sin_addr));

   // printf("Send Msg...\n");


    bzero(data_buf,sizeof(data_buf));
    i=recv(client_sockfd,data_buf,sizeof(data_buf),0);

    printf("*********(%d)bytes recv******\n",i);
    printf("data_buf=%s\n",data_buf);
    printf("+++++++++++++++++++++++++++++\n");

    if(0==strncmp(data_buf,"GET / HTTP",10)) //发送网页文件
    {
        FILE *fp;
        fp=fopen("my.html","r");
        lstat("my.html",&statbuf);

        bzero(data_buf,sizeof(data_buf));
        sprintf(data_buf,"HTTP/1.1 200 OK\r\nContent-Type: text/html\r\nContent-Length: %ld\r\n\r\n",statbuf.st_size);

        int file_length;
        do
        {
           file_length=fread(data_buf,sizeof(char),2048,fp);

           i=send(client_sockfd,data_buf,strlen(data_buf),0);
          // printf("send html bytes:i=%d\n",i);
           bzero(data_buf,sizeof(data_buf));
        }while(file_length>0);


        fclose(fp);


    }

    else //根据浏览器的请求发送文件
    {
    char fileinfo[SIZE]; //获取请求的文件路径和文件名
    bzero(fileinfo,100);
    char buff[SIZE];
    bzero(buff,sizeof(buff));

    sscanf(data_buf,"%*[^/]/%[^ ]",buff);
    printf("file name buff=%s\n",buff);

    char a[2]={'/'};
    //fileinfo[SIZE]={'/'};
    strcat(fileinfo,a);
    strcat(fileinfo,buff);

    printf("fileinfo=%s\n",fileinfo);

    //if(0==strncmp(data_buf,"GET /home/",10)) //发送图片
    //{
        printf("Send  jpg...\n");
        FILE *fp;
        fp=fopen(fileinfo,"r");
        if(fp==NULL)
        {
            perror("fopen failed:");
        }
        lstat(fileinfo,&statbuf); //获取文件属性

        bzero(data_buf,sizeof(data_buf));
        sprintf(data_buf,"HTTP/1.1 200 OK\r\nContent-Type: image/jpg\r\nContent-Length: %ld\r\n\r\n",statbuf.st_size);

        printf("statbuf.st_size=%ld\n",statbuf.st_size);


        int file_block_length;

       do
       {
       file_block_length=fread(data_buf,1,2048,fp);
       printf("file_block_length=%d\n",file_block_length);


     // printf("data_buf=%s\n",data_buf);
       i=send(client_sockfd,data_buf,2048,0);

       printf("send byte i=%d\n",i);
       }while(file_block_length>0);

       printf("send over \n");
       fclose(fp);

    }

    close(client_sockfd);
    }

}