Question

linux环境下，c语言怎么读取WEB服务器的80端口上页面的内容

Answer 1

已知url ,host, port;

int s, size;
struct sockaddr_in sin;
struct hostent* phe;
char cmd[256];
char msg_hdr[1000];
char* p;

//准备http中GET 方法的请求。
sprintf(cmd,"GET %s\r\nHTTP/1.1\r\nHost:%s", url, host);
//创建socket
if((s=socket(PF_INET,SOCK_STREAM,0))<0)
return -1;
//取得远程主机的IP地址，失败函数返回－1
if((phe = gethostbyname(host)) == NULL)
return -1;

memset(&sin,0,sizeof(sin));
memcpy(&sin.sin_addr,phe->h_addr,sizeof(struct in_addr));
sin.sin_family=AF_INET;
sin.sin_port=htons(pms->port);

//跟远程机器建立连接，失败函数返回－1
if(connect(s,(struct sockaddr*)&sin,sizeof(sin))==-1)
return -1;
//发送GET请求
if(write(s,cmd,strlen(cmd))<0)
return 0;

//从链接描述符（连接管道）中读取传送过来的数据
if(read(s, msg_hdr, 300)<0)
error;
close(s);

//读到该文件的大小
if((p=strstr(msg_hdr,"Content-Length"))||(p=strstr(msg_hdr,"Content-length:")))
p+=16;
else
error;
//返回大小
size = atoi(p);

sprintf(cmd,"GET %s HTTP/1.1\r\nHost: %s\r\nAccept: */*\r\nPragma: no-cache\r\nCache-Control: no-cache\r\nConnection: close\r\nRange: bytes0-%d\r\n\r\n", url, host, size);
//创建套接口
if((s=socket(AF_INET,SOCK_STREAM,0))<0)
return 0;
//取得远程主机的IP地址，失败返回0
if((phe = gethostbyname(host)) == NULL)
return 0;
memset(&sin,0,sizeof(sin));
memcpy(&sin.sin_addr,phe->h_addr,sizeof(struct in_addr));
sin.sin_family=AF_INET;
sin.sin_port=htons(port);
//建立连接
if(connect(s,(struct sockaddr*)&sin,sizeof(sin))==-1)
return 0;
//发送读取请求
if(write(s,cmd,strlen(cmd))<0)
error;
read(s, buf, BUFSIZE)..............