When facing login issues or parse errors related to unexpected characters in PHP files, what alternative methods can be employed to access and modify the affected files, such as using the host's database or replacing the function.php file in the theme?

When facing login issues or parse errors related to unexpected characters in PHP files, one alternative method to access and modify the affected files is by using the host's database to edit the content directly. Another approach is to replace the function.php file in the theme with a clean version to eliminate any unexpected characters causing the error.

// Example code to replace function.php file in the theme with a clean version
$theme_directory = get_template_directory();
$original_function_file = $theme_directory . '/functions.php';
$clean_function_file = $theme_directory . '/functions-clean.php';

// Copy the clean functions.php file to the theme directory
copy($clean_function_file, $original_function_file);