Re: File name regular expression

mmmmmmmm... watch those periods... they are the wildcard and need to be escaped... following not tested...

^pfi_[A-Za-z0-9]+\.xml$

As for the $, it means nothing else follows except newline, carriage return, it's the end of the string and match at the end. In other words, the '.xml' must come at the end of the string. The ^ just means match at the beginning of the string. So the 'pfi_' must come first, before anything else.

The + means that at least one matching character from the [] group is found after the underscore. The \ escapes the . so it's treated as a real period, and not the wildcard.

On 05/03/2010 02:59 PM, Dennis Lovelady wrote:

I am attempting to match a file name pattern to file names read from an
IFS directory. What I want is the pattern pfi_nnnn.xml. The files I
want will begin with 'pfi_', and end with '.xml'. Currently there are
10 digits in between but I wanted to be able to handle varying numbers.
My expression compiles ok but it doesn't match the file names. Doing
more research on the web makes me think I'm pretty close but hasn't
given me clear direction about the use of the '^' and '$' symbols for
matching the beginning and end of a string. In particular, the end of
a string. I am attempting to match '.xml' using (.xml)$. My reading
has me wondering if $ only matches the last character and not multiple
characters. Hopefully someone on the list can help me out with this.
I am posting my current expression below.


^(pfi_)[A-Z0-9](.xml)$

You're so close!

I would do ^pfi[A-Z0-9]*.xml*. There's no advantage that I see so your
parentheses.

(It's the missing splat that's killing you now.)

Dennis Lovelady
http://www.linkedin.com/in/dennislovelady
--
Hard work pays off in the future. Laziness pays off now.