uristrings.c

// ========================================================================
//
//  Project   : statsproxy 
//
//  Version   : 1.0
//
//  Copyright :
//
//      Software License Agreement (BSD License)
//
//      Copyright (c) 2009, Gear Six, Inc.
//      All rights reserved.
//
//      Redistribution and use in source and binary forms, with or without
//      modification, are permitted provided that the following conditions are
//      met:
//
//      * Redistributions of source code must retain the above copyright
//        notice, this list of conditions and the following disclaimer.
//
//      * Redistributions in binary form must reproduce the above
//        copyright notice, this list of conditions and the following disclaimer
//        in the documentation and/or other materials provided with the
//        distribution.
//
//      * Neither the name of Gear Six, Inc. nor the names of its
//        contributors may be used to endorse or promote products derived from
//        this software without specific prior written permission.The Gear Six logo, 
//        which is provided in the source code and appears on the user interface 
//        to identify Gear Six, Inc. as the originator of the software program, is 
//        a trademark of Gear Six, Inc. and can be used only in unaltered form and 
//        only for purposes of such identification.
//
//      THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
//      "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
//      LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// ========================================================================
//
/* derived from http://www.geekhideout.com/uricode.shtml */

#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <assert.h>
#include "proxylog.h"
#include "uristrings.h"

/* Converts a hex character to its integer value */
static char
from_hex(char ch) {
  return isdigit(ch) ? ch - '0' : tolower(ch) - 'a' + 10;
}

/* Converts an integer value to its hex character*/
static char
to_hex(char code) {
  static char hex[] = "0123456789abcdef";
  return hex[code & 15];
}

/* Returns a uri-encoded version of str */
/* IMPORTANT: be sure to free() the returned string after use */
char *uri_encode(const char *str) {
  const char *pstr = str;
  char *buf = (char *) malloc(strlen(str) * 3 + 1), *pbuf = buf;
  alloc_fail_check(buf);
  while (*pstr) {
    if (isalnum(*pstr) || *pstr == '-' || *pstr == '_' || *pstr == '.' ||
        *pstr == '~') 
      *pbuf++ = *pstr;
    else if (*pstr == ' ') 
      *pbuf++ = '+';
    else 
      *pbuf++ = '%', *pbuf++ = to_hex(*pstr >> 4), *pbuf++ = to_hex(*pstr & 15);
    pstr++;
  }
  *pbuf = '\0';
  return buf;
}

/* Returns a uri-decoded version of str */
/* IMPORTANT: be sure to free() the returned string after use */
char *uri_decode(const char *str) {
  const char *pstr = str;
  char *buf = (char *) malloc(strlen(str) + 1), *pbuf = buf;
  alloc_fail_check(buf);
  while (*pstr) {
    if (*pstr == '%') {
      if (pstr[1] && pstr[2]) {
        *pbuf++ = from_hex(pstr[1]) << 4 | from_hex(pstr[2]);
        pstr += 2;
      }
    } else if (*pstr == '+') { 
      *pbuf++ = ' ';
    } else {
      *pbuf++ = *pstr;
    }
    pstr++;
  }
  *pbuf = '\0';
  return buf;
}