Can you please give us some context? Where did you dig this up, which tool/language
was it in? While 'regex' is a fairly well-known concept just about any tool you
touch that uses regex' will have a slightly different implementation.
If I assumed that the above was out of e.g., a perl snippet I'd break it up like so,
and would have to say that it's a weird (poorly written) regex:
Match anything that is either
Beginning of line, followed by any number of '\' followed by a backslash (the one behind the * doesn't make sense).
the string local7 followed by any number of anything followed by any number of whitespace
followed by \/ followed by any number of lower case characters.
All up it makes little sense.