If you are unsure how regular expression syntax should work (in industry-wide practice), there are many books and online references, for example
http://en.wikipedia.org/wiki/Regular_expression#POSIX_Basic_Regular_Expressions
If you are unsure how regular expression syntax should work (in industry-wide practice), there are many books and online references, for example
http:// en.wikipedia. org/wiki/ Regular_ expression# POSIX_Basic_ Regular_ Expressions