/**   *@brief 对于url中的一些特殊字符会被转义以利传输,   *      并且， 归档服务器上, php写入cookie中的值可能存在特殊字符， 需要转换   *           *参考: http://www.blooberry.com/indexdot/html/topics/urlencoding.htm   *      http://www.december.com/html/spec/esccodes.html   *   *@param[in,out] data 需要处理的数据， 处理完后， 这个数据会被修改为期待的数据   *@param[in] data_len data中的实际数据长度   *   */  int escape_url_character(char *data, int data_len)  {      /* 下面只列出来了一些加密用到的字符， 而没有列出所有的字符, 主要是空格, /, +, = */      char *transfer_table[][2] = { {"+", "2B"}, {"[","5B"},{"]","5D"},{"`","60"},{";","3B"},{"/","2F"},{"?","3F"},{":","3A"},{"@","40"},{"=","3D"},{"&","26"},{"$","24"},{" ","20"},{"<","3C"},{">","3E"},{"#","23"},{"%","25"},{"{","7B"},{"}","7D"},{"|","7C"},{"\\","5C"},{"^","5E"},{"~","7E"}, {NULL, NULL} };         int i = 0, j;      char *buf = calloc(data_len + 1, sizeof(char));         while( i < data_len ){          if( '%' != data[i]){              strncat(buf, data+i, 1);              i++;              continue;          }             /* 查表 */          j = 0;          while( NULL != transfer_table[j][1] ){              if( 0 == strncasecmp(data+i+1, transfer_table[j][1], 2 )){                  strncat(buf, transfer_table[j][0], 1);                  i += 3;                  break;              }              j++;          }          /* 对于表中不存在的字符不作处理, 但输出一条日志 */          if( NULL == transfer_table[j][1] ){              strncat(buf, data+i, 1);              printf("escape_url_character: unhandled sequence: %s\n", data+i);              i++;          }      }         memset(data, 0, data_len);      strcpy(data, buf);         free(buf);      return 0;  }