Question

I have the following patterns and grouping application which I am refactoring in one. The following will be placed in a xml file and read into a regex engine:

 regexpattern="http://cars.mysite.com(.*)" application="http://www.mysite.com$1"

  regexpattern="http://ww.mysite.com(.*)" application="http://www.mysite.com$1 

    regexpattern="http://(bikes\.|new\.|)mysite.com/(.*)" application="http://www.mysite.com/$2"

combined into this:

regexpattern="http://(cars\.|ww\.|bikes\.|new\.|)mysite.com(|/)(.*)"  application="http://www.mysite.com/$3"

Is this the best I could do, can it be done better? I am new to this. Thanks.

Answer 1

1. You have a missing backslash:

http://(cars\.|ww\.|bikes\.|new\.|)mysite\.com(|/)(.*)
                                         ^

2. Instead of (|/) you can use /?:

http://(cars\.|ww\.|bikes\.|new\.|)mysite\.com/?(.*)
                                              ^^

3. Making the slash optional means that it accepts things like mysite.com.co.uk which is probably not what you want.

4. Another minor change is to write \. only once:

http://((cars|ww|bikes|new)\.)?mysite\.com/?(.*)
                           ^^