学步园

鉴于有时要用C++ 写CGI，url encode、decode是必不可少的，有必要单独整理下。这里吐槽下，C++做web真是笨重，没有python、php爽。

http://blog.csdn.net/nanjunxiao/article/details/9303619之前写过一个简单的encode，这里补充更新下。

#include <string>
#include <iostream>
using namespace std;

//static const char safe[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
static const char safe[]={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,0,1,1,0,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,1,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

std::string encode(const std::string &uri)
{
	string ret;	
	const unsigned char *ptr = (const unsigned char *)uri.c_str();
	ret.reserve(uri.length());

	for (; *ptr ; ++ptr)
	{
		if (!safe[*ptr]) 
		{
			char buf[5];
			memset(buf, 0, 5);
#ifdef WIN32
			_snprintf_s(buf, 5, "%%%X", (*ptr));
#else
			snprintf(buf, 5, "%%%X", (*ptr));
#endif
			ret.append(buf); 	
		}
		else if (*ptr==' ')
		{
			ret+='+';
		}
		else{
			ret += *ptr;
		}
	}
	return ret;
}

std::string decode(const std::string &uri)
{
	//Note from RFC1630:  "Sequences which start with a percent sign
	//but are not followed by two hexadecimal characters (0-9,A-F) are reserved
	//for future extension"
	const unsigned char *ptr = (const unsigned char *)uri.c_str();
	string ret;
	ret.reserve(uri.length());
	for (; *ptr; ++ptr)
	{
		if (*ptr == '%')
		{
			if (*(ptr + 1))
			{
				char a = *(ptr + 1);
				char b = *(ptr + 2);
				if (!((a >= 0x30 && a < 0x40) || (a >= 0x41 && a < 0x47))) continue;
				if (!((b >= 0x30 && b < 0x40) || (b >= 0x41 && b < 0x47))) continue;
				char buf[3];
				buf[0] = a;
				buf[1] = b;
				buf[2] = 0;
				ret += (char)strtoul(buf, NULL, 16);
				ptr += 2;
				continue;
			}
		}
		if (*ptr=='+')
		{
			ret+=' ';
			continue;
		}
		ret += *ptr;
	}
	return ret;
}