// @descr: enumerates all variables(user and system) by index
// USER SCOPE: [0 .. user var count - 1]
// SYSTEM SCOPE: [user var count .. system var count - 1]
BOOL winapi_read_by_index(int index, int* out_scope, char** out_name, char** out_value)
{
/// vars ///
HKEY hKey;
int current_scope = -1;
/// decide which scope index belongs to ///
/// and open key containing the requested variable ///
int user_scope_var_count = winapi_var_count_scope(USER_SCOPE);
if (index >= user_scope_var_count) // system range
{
index = index - user_scope_var_count; // convert index to system range
if (index >= winapi_var_count_scope(SYSTEM_SCOPE))
return FALSE; // out of range -> fail
open_variables_key(SYSTEM_SCOPE, &hKey);
current_scope = SYSTEM_SCOPE;
} else if (index >= 0) // user range
{ // index doesn't need adjustment
open_variables_key(USER_SCOPE, &hKey);
current_scope = USER_SCOPE;
} else
{
return FALSE; // out of range -> fail
}
// allocate temp buffers on stack for name and value
char name_buffer [sizeof(char)*(get_longest_name(hKey)+1)];
char value_buffer [sizeof(char)*(get_longest_value(hKey)+1)];
name_buffer[0]=0; // null terminate
value_buffer[0]=0;
// buffer size / bytes copied to buffer
DWORD in_out_name_size = sizeof(name_buffer);
DWORD in_out_value_size = sizeof(value_buffer);
/// retrieve name and value into buffers ///
RegEnumValue(hKey,
index,
name_buffer,
&in_out_name_size, // size not including the terminating 0
0,
NULL,
value_buffer,
&in_out_value_size); // likewise
RegCloseKey(hKey);
/// allocate and copy to new heap buffers, return them through output arguments ///
*out_name = malloc(in_out_name_size + 1); // + 1 for null terminator
memcpy(*out_name, name_buffer, in_out_name_size + 1); // copy string + null terminator
*out_value = malloc(in_out_value_size+1);
memcpy(*out_value, value_buffer, in_out_value_size + 1);
*out_scope = current_scope;
return TRUE;
};
/**
* Get the longest name (by UTF-8 length) in the set.
*
* Returns: The longest nontrivial name, or "" if none.
*/
const std::string& get_longest_name()
{
return get_longest_name(set::utflength_rate);
}
