用vc6提供的方法，哪种方法能够很稳定地读取网页内容（能够兼容死链接而不过于超时）？

[ac1998]

用vc6提供的方法，哪种方法能够很稳定地读取网页内容（能够兼容死链接而不过于超时）？

我用组件读取，不是很稳定，用CHttpFile，好了一些，但依然不是非常稳定。

请教网络编程高手。

[DJay]

试试看CHttpClient咯，听说不错，但我没试过使用控件的，如果你要性能和灵活性比较好，干吗不直接从socket自己写呢

[折腾_苏州]

WinInet??

[DentistryDoctor]

不稳定，应该是代码的问题。

[ac1998]

不稳定的表现不是程序死掉，而是很多读取线程很久都没有结束。最长的有读死链接而导致3-4个小时线程才结束的情况。

我想达到的目的是读取网页，如果长时间没动静，干脆终止读取任务线程。

[ac1998]

up.

[jacklzw88]

WinInet应该比较稳定，长时间没反应，可能就是连接不上，或者请求发出去了，服务器没返回，无限期等待了，所以你要做判断

[蒋晟]

自己设个时钟判断超时啦

[song x]

能自己判断超时吗?如果在接收数据时一直在等待,如果去判断时间?

[song x]

/*
* on Unix:
* cc -c connector.c
* cc -o connector connector.o
*
* on Windows NT:
* open connector.c in Visual Studio
* press 'F7' to link -- a project to be created
* add wsock32.lib to the link section under project setting
* press 'F7' again
*
* running:
* type 'connector' for usage
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <errno.h>
#include <fcntl.h>
#ifdef WIN32
#include <winsock2.h>
#else
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#endif

#ifndef INADDR_NONE
#define INADDR_NONE 0xffffffff
#endif
#define MAX_STRING_LEN 1024
#define BUFSIZE 2048

#ifndef WIN32
#define SOCKET int
#else
#define errno WSAGetLastError()
#define close(a) closesocket(a)
#define write(a, b, c) send(a, b, c, 0)
#define read(a, b, c) recv(a, b, c, 0)
#endif

char buf[BUFSIZE];

static char i_host[MAX_STRING_LEN]; /* site name */
static char i_port[MAX_STRING_LEN]; /* port number */

void err_doit(int errnoflag, const char *fmt, va_list ap);
void err_quit(const char *fmt, ...);
int tcp_connect(const char *host, const unsigned short port);
void print_usage();

//xnet_select x defines
#define READ_STATUS 0
#define WRITE_STATUS 1
#define EXCPT_STATUS 2

/*
s - SOCKET
sec - timeout seconds
usec - timeout microseconds
x - select status
*/
SOCKET xnet_select(SOCKET s, int sec, int usec, short x)
{
int st = errno;
struct timeval to;
fd_set fs;
to.tv_sec = sec;
to.tv_usec = usec;
FD_ZERO(&fs);
FD_SET(s, &fs);
switch(x){
case READ_STATUS:
st = select(s+1, &fs, 0, 0, &to);
break;
case WRITE_STATUS:
st = select(s+1, 0, &fs, 0, &to);
break;
case EXCPT_STATUS:
st = select(s+1, 0, 0, &fs, &to);
break;
}
return(st);
}

int tcp_connect(const char *host, const unsigned short port)
{
unsigned long non_blocking = 1;
unsigned long blocking = 0;
int ret = 0;
char * transport = "tcp";
struct hostent *phe; /* pointer to host information entry */
struct protoent *ppe; /* pointer to protocol information entry*/
struct sockaddr_in sin; /* an Internet endpoint address */
SOCKET s; /* socket descriptor and socket type */
int error;

#ifdef WIN32
{
WORD wVersionRequested;
WSADATA wsaData;
int err;

wVersionRequested = MAKEWORD( 2, 0 );

err = WSAStartup( wVersionRequested, &wsaData );
if ( err != 0 ) {
/* Tell the user that we couldn't find a usable */
/* WinSock DLL. */
printf("can't initialize socket library\n");
exit(0);
}
}
#endif

memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;

if ((sin.sin_port = htons(port)) == 0)
err_quit("invalid port \"%d\"\n", port);

/* Map host name to IP address, allowing for dotted decimal */
if ( phe = gethostbyname(host) )
memcpy(&sin.sin_addr, phe->h_addr, phe->h_length);
else if ( (sin.sin_addr.s_addr = inet_addr(host)) == INADDR_NONE )
err_quit("can't get \"%s\" host entry\n", host);

/* Map transport protocol name to protocol number */
if ( (ppe = getprotobyname(transport)) == 0)
err_quit("can't get \"%s\" protocol entry\n", transport);

/* Allocate a socket */
s = socket(PF_INET, SOCK_STREAM, ppe->p_proto);
if (s < 0)
err_quit("can't create socket: %s\n", strerror(errno));

/* Connect the socket with timeout */
#ifdef WIN32
ioctlsocket(s,FIONBIO,&non_blocking);
#else
ioctl(s,FIONBIO,&non_blocking);
#endif
//fcntl(s,F_SETFL, O_NONBLOCK);
if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) == -1){
struct timeval tv;
fd_set writefds;
// 设置连接超时时间
tv.tv_sec = 10; // 秒数
tv.tv_usec = 0; // 毫秒
FD_ZERO(&writefds);
FD_SET(s, &writefds);
if(select(s+1,NULL,&writefds,NULL,&tv) != 0){
if(FD_ISSET(s,&writefds)){
int len=sizeof(error);
//下面的一句一定要，主要针对防火墙
if(getsockopt(s, SOL_SOCKET, SO_ERROR, (char *)&error, &len) < 0)
goto error_ret;
if(error != 0)
goto error_ret;
}
else
goto error_ret; //timeout or error happen
}
else goto error_ret; ;

#ifdef WIN32
ioctlsocket(s,FIONBIO,&blocking);
#else
ioctl(s,FIONBIO,&blocking);
#endif

}
else{
error_ret:
close(s);
err_quit("can't connect to %s:%d\n", host, port);
}
return s;
}

void err_doit(int errnoflag, const char *fmt, va_list ap)
{
int errno_save;
char buf[MAX_STRING_LEN];

errno_save = errno;
vsprintf(buf, fmt, ap);
if (errnoflag)
sprintf(buf + strlen(buf), ": %s", strerror(errno_save));
strcat(buf, "\n");
fflush(stdout);
fputs(buf, stderr);
fflush(NULL);
return;
}

[song x]

/* Print a message and terminate. */
void err_quit(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
err_doit(0, fmt, ap);
va_end(ap);
exit(1);
}

#ifdef WIN32
char *optarg;

char getopt(int c, char *v[], char *opts)
{
static int now = 1;
char *p;

if (now >= c) return EOF;

if (v[now][0] == '-' && (p = strchr(opts, v[now][1]))) {
optarg = v[now+1];
now +=2;
return *p;
}

return EOF;
}

#else
extern char *optarg;
#endif

#define required(a) if (!a) { return -1; }

int init(int argc, char *argv[])
{
char c;
//int i,optlen;
//int slashcnt;

i_host[0] = '\0';
i_port[0] = '\0';

while ((c = getopt(argc, argv, "h:p:?")) != EOF) {
if (c == '?')
return -1;
switch (c) {
case 'h':
required(optarg);
strcpy(i_host, optarg);
break;
case 'p':
required(optarg);
strcpy(i_port, optarg);
break;
default:
return -1;
}
}

/*
* there is no default value for hostname, port number,
* password or uri
*/
if (i_host[0] == '\0' || i_port[0] == '\0')
return -1;

return 1;
}

void print_usage()
{
char *usage[] =
{
"Usage:",
" -h host name",
" -p port",
"example:",
" -h 127.0.0.1 -p 4001",
};
int i;

for (i = 0; i < sizeof(usage) / sizeof(char*); i++)
printf("%s\n", usage[i]);

return;
}

int main(int argc, char *argv[])
{
SOCKET fd;
int n;

/* parse command line etc ... */
if (init(argc, argv) < 0) {
print_usage();
exit(1);
}

buf[0] = '\0';

/* pack the info into the buffer */
strcpy(buf, "HelloWorld");

/* make connection to the server */
fd = tcp_connect(i_host, (unsigned short)atoi(i_port));

if(xnet_select(fd, 0, 500, WRITE_STATUS)>0){
/* send off the message */
write(fd, buf, strlen(buf));
}
else{
err_quit("Socket I/O Write Timeout %s:%s\n", i_host, i_port);
}

if(xnet_select(fd, 3, 0, READ_STATUS)>0){
/* display the server response */
printf("Server response:\n");
n = read(fd, buf, BUFSIZE);
buf[n] = '\0';
printf("%s\n", buf);
}
else{
err_quit("Socket I/O Read Timeout %s:%s\n", i_host, i_port);
}
close(fd);

#ifdef WIN32
WSACleanup();
#endif

return 0;
}