如何制作类似于Internet Download Manager的程序,以便从互联网下载给定链接的文件。可以使用C语言套接字编程从互联网下载文件。
非常感谢您的帮助。
socket()
创建一个套接字。connect()
。send()
或write()
正确发送一个GET /path/filename HTTP/1.0\r\n\r\n
请求。recv()
或read()
正确接收响应。recv()
或read()
接收它。close()
关闭套接字。进一步阅读:
#include<stdio.h>
#include<string.h>
#include<sys/socket.h>
#include<arpa/inet.h>
// www.axmag.com/download/pdfurl-guide.pdf
int main(int argc , char *argv[])
{
int socket_desc;
char *message;
char server_reply[10000];
char *filename = "file.pdf";
int total_len = 0;
int file_len = 99352;
int len;
FILE *file = NULL;
struct sockaddr_in server;
//Create socket
socket_desc = socket(AF_INET , SOCK_STREAM , 0);
if (socket_desc == -1)
{
printf("Could not create socket");
}
server.sin_addr.s_addr = inet_addr("198.11.181.184");
server.sin_family = AF_INET;
server.sin_port = htons( 80 );
//Connect to remote server
if (connect(socket_desc , (struct sockaddr *)&server , sizeof(server)) < 0)
{
puts("connect error");
return 1;
}
puts("Connected\n");
//Send request
message = "GET /download/pdfurl-guide.pdf HTTP/1.1\r\nHost: www.axmag.com\r\n\r\n Connection: keep-alive\r\n\r\n Keep-Alive: 300\r\n";
if( send(socket_desc , message , strlen(message) , 0) < 0)
{
puts("Send failed");
return 1;
}
puts("Data Send\n");
remove(filename);
file = fopen(filename, "ab");
if(file == NULL){
printf("File could not opened");
}
while(1)
{
int received_len = recv(socket_desc, server_reply , sizeof server_reply , 0);
if( received_len < 0 ){
puts("recv failed");
break;
}
total_len += received_len;
//puts(server_reply);
fwrite(server_reply , received_len , 1, file);
printf("\nReceived byte size = %d\nTotal lenght = %d", received_len, total_len);
if( total_len >= file_len ){
break;
}
}
puts("Reply received\n");
fclose(file);
return 0;
}
/html/index.html
。 - alkGET
行中不要包含主机名。你需要使用单独的Host
行来指定主机名:GET /file.pdf HTTP/1.1\r\nHost: www.site.com\r\n\r\n
- Remy Lebeau