使用HTTP GET请求C时不libcurl的 [英] HTTP get Request using C WITHOUT libCurl

问题描述

我想写一个C程序来生成一个GET请求，而无需使用任何外部库。仅使用C库，使用套接字这可能吗？我想制作一个HTTP数据包（使用正确的格式），并将其发送给服务器。这是唯一可行的方法，或是否有更好的办法？

I want to write a C program to generate a Get Request without using any external libraries. Is this possible using only C libraries, using sockets ? I'm thinking of crafting a http packet(using proper formatting) and sending it to the server. Is this the only possible way or is there a better way ?

推荐答案

使用BSD套接字或者，如果你是比较有限的，说你有一些RTOS，一些简单的TCP协议栈，LWIP的一样，可以形成GET / POST请求。

Using BSD sockets or, if you're somewhat limited, say you have some RTOS, some simpler TCP stack, like lwIP, you can form the GET/POST request.

有许多开源实现。请参阅happyhttp为样本（ http://scumways.com/happyhttp/happyhttp.html ）。我知道，这是C ++，不是C，但是这是唯一的C ++ - 依赖有一个字符串/阵列管理，所以很容易移植到纯C

There are a number of open-source implementations. See the "happyhttp" as a sample ( http://scumways.com/happyhttp/happyhttp.html ). I know, it is C++, not C, but the only thing that is "C++-dependant" there is a string/array management, so it is easily ported to pure C.

当心，有没有三包，因为HTTP通常是转移通过TCP连接，所以在技术上，只有在RFC格式符号流。由于HTTP请求的一个连接，发送断开的方式通常做的，人们实际上可能称之为包。

Beware, there are no "packets", since HTTP is usually transfered over the TCP connection, so technically there is only a stream of symbols in RFC format. Since http requests are usually done in a connect-send-disconnect manner, one might actually call this a "packet".

基本上，一旦你有一个开放的插座（的sockfd）的全部你必须做的是一样的东西。

Basically, once you have an open socket (sockfd) "all" you have to do is something like

char sendline[MAXLINE + 1], recvline[MAXLINE + 1];
char* ptr;

size_t n;

/// Form request
snprintf(sendline, MAXSUB, 
     "GET %s HTTP/1.0\r\n"  // POST or GET, both tested and works. Both HTTP 1.0 HTTP 1.1 works, but sometimes 
     "Host: %s\r\n"     // but sometimes HTTP 1.0 works better in localhost type
     "Content-type: application/x-www-form-urlencoded\r\n"
     "Content-length: %d\r\n\r\n"
     "%s\r\n", page, host, (unsigned int)strlen(poststr), poststr);

/// Write the request
if (write(sockfd, sendline, strlen(sendline))>= 0) 
{
    /// Read the response
    while ((n = read(sockfd, recvline, MAXLINE)) > 0) 
    {
        recvline[n] = '\0';

        if(fputs(recvline,stdout) == EOF) { cout << ("fputs erros"); }
        /// Remove the trailing chars
        ptr = strstr(recvline, "\r\n\r\n");

        // check len for OutResponse here ?
        snprintf(OutResponse, MAXRESPONSE,"%s", ptr);
    }          
}

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