Question

The following .bat file does not produce an error. Why?

@@@@@@@@@@@@@@@
:::::::::::::::
;;;;;;;;;;;;;;;
===============
=;=;=;=;=;=;=;=
;=;=;=;=;=;=;=;

I know the ‘@’ line prefix means “do not echo” and the :: prefix means “this is a comment”, but what do the ; and = do?

As far as I can tell you can start a line with any mixture of ‘;’ and ‘=’ symbols and it has no effect whatsoever. =;=;=;=;=;=dir does execute dir. What is the correct interpretation of ‘=’ and ‘;’ ?

Answer 1

They are interpreted as command line delimiters (along with a comma and white-space characters) so the following are all equivalent;

dir c:\ /b
dir c:\;/b
dir c:\=/b
dir c:\,/b

In the case of =;=;=;=;=;=dir they are presumably treated as leading white-space and ignored