% 0a what can be done

If this regular expression is used but a % 0a is introduced, the vulnerability returns to what % 0a can do!
The following is a summary of the black box, in the extension Suffix of the file.

1.php.jpg cannot be executed
1.php.jpg % 0a (in Linux)

In addition, if % 0a is a new row when writing a file, it is a new record when the database is text.

What else? The database treats 1 and 1% a differently, and 1% A is updated to an int type field, which may cause overflow.

In some protocols such as HTTP and FTP, % 0a can be the beginning of a new command.