urlcode.cpp

#include "urlcode.h"

char UrlCode::FromHex(char ch)
{
	return isdigit(ch) ? ch - '0' : tolower(ch) - 'a' + 10;
}

char UrlCode::ToHex(char code)
{
	static char hex[] = "0123456789abcdef";
	return hex[code & 15];
}

std::string UrlCode::Decode(std::string url)
{
	const char *pstr = url.c_str();
	char *buf = new char[url.length() + 1];
	char *pbuf = buf;

	while (*pstr) {
		if (*pstr == '%') {
			if (pstr[1] && pstr[2]) {
				*pbuf++ = FromHex(pstr[1]) << 4 | FromHex(pstr[2]);
				pstr += 2;
			}
		} else if (*pstr == '+') { 
			*pbuf++ = ' ';
		} else {
			*pbuf++ = *pstr;
		}
		pstr++;
	}

	*pbuf = '\0';

	std::string decoded = buf;
	delete buf;

	return decoded;
}

std::string UrlCode::Encode(std::string url)
{
	const char *pstr = url.c_str();
	char *buf = new char[url.length() * 3 + 1];
	char *pbuf = buf;

	while (*pstr) {
		if (isalnum(*pstr) || *pstr == '-' || *pstr == '_' || *pstr == '.' || *pstr == '~') {
			*pbuf++ = *pstr;
		} else if (*pstr == ' ') {
			*pbuf++ = '+';
		} else {
			*pbuf++ = '%';
			*pbuf++ = ToHex(*pstr >> 4);
			*pbuf++ = ToHex(*pstr & 15);
		}

		pstr++;
	}

	*pbuf = '\0';

	std::string encoded = buf;
	delete buf;

	return encoded;
}