CODEWITHSUNDEEP
c++http
Rono
Rono

Reputation: 153

Encode/Decode URl In C++

How can i encode a URL in client side and Decode the same in Server side.Is there any Built in apis are available for this purpose.Please anyone suggest a solution.Also i want to know how can i do percentage encoding in C++?

Upvotes: 5

Views: 21614

Answers (3)

Vineet Mimrot
Vineet Mimrot

Reputation: 109

For Encoding:

You can use "g_uri_escape_string()" function provided glib.h. https://developer.gnome.org/glib/stable/glib-URI-Functions.html

#include <stdio.h>
#include <stdlib.h>
#include <glib.h>
int main() {
    char *uri = "http://www.example.com?hello world";
    char *encoded_uri = NULL;
    //as per wiki (https://en.wikipedia.org/wiki/Percent-encoding)
    char *escape_char_str = "!*'();:@&=+$,/?#[]"; 
    encoded_uri = g_uri_escape_string(uri, escape_char_str, TRUE);
    printf("[%s]\n", encoded_uri);
    free(encoded_uri);

    return 0;
}

compile it with:

gcc encoding_URI.c `pkg-config --cflags --libs glib-2.0`

Upvotes: 1

strangeqargo
strangeqargo

Reputation: 1272

I've found this implementation from dlib quite useful. You don't even need to grab the whole library, just these 4 functions (unhex, hex, encode, decode). And it has a boost license.

Upvotes: 9

Rahul Tripathi
Rahul Tripathi

Reputation: 172428

You can check out this article and this

Encode:

std::string UriEncode(const std::string & sSrc)
{
   const char DEC2HEX[16 + 1] = "0123456789ABCDEF";
   const unsigned char * pSrc = (const unsigned char *)sSrc.c_str();
   const int SRC_LEN = sSrc.length();
   unsigned char * const pStart = new unsigned char[SRC_LEN * 3];
   unsigned char * pEnd = pStart;
   const unsigned char * const SRC_END = pSrc + SRC_LEN;

   for (; pSrc < SRC_END; ++pSrc)
   {
      if (SAFE[*pSrc]) 
         *pEnd++ = *pSrc;
      else
      {
         // escape this char
         *pEnd++ = '%';
         *pEnd++ = DEC2HEX[*pSrc >> 4];
         *pEnd++ = DEC2HEX[*pSrc & 0x0F];
      }
   }

   std::string sResult((char *)pStart, (char *)pEnd);
   delete [] pStart;
   return sResult;
}

Decode:

std::string UriDecode(const std::string & sSrc)
{
   // 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 * pSrc = (const unsigned char *)sSrc.c_str();
   const int SRC_LEN = sSrc.length();
   const unsigned char * const SRC_END = pSrc + SRC_LEN;
   // last decodable '%' 
   const unsigned char * const SRC_LAST_DEC = SRC_END - 2;

   char * const pStart = new char[SRC_LEN];
   char * pEnd = pStart;

   while (pSrc < SRC_LAST_DEC)
   {
      if (*pSrc == '%')
      {
         char dec1, dec2;
         if (-1 != (dec1 = HEX2DEC[*(pSrc + 1)])
            && -1 != (dec2 = HEX2DEC[*(pSrc + 2)]))
         {
            *pEnd++ = (dec1 << 4) + dec2;
            pSrc += 3;
            continue;
         }
      }

      *pEnd++ = *pSrc++;
   }

   // the last 2- chars
   while (pSrc < SRC_END)
      *pEnd++ = *pSrc++;

   std::string sResult(pStart, pEnd);
   delete [] pStart;
   return sResult;
}

Upvotes: 6

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