Solved

regular expression validation

Posted on 2012-04-03
2
235 Views
Last Modified: 2012-04-09
I'm using the followin regular expression validator.  

ValidationExpression="^([a-zA-Z].*|[0-9].*)\.(((p|P)(d|D)(f|F))|((d|D)(o|O)(c|C))|((p|P)(d|D)(f|F))|((d|D)(o|O)(c|C)(x|X))|((t|T)(i|I)(f|F))|((t|T)(i|I)(f|F)(f|F))|((w|W)(p|P)(s|S))|((w|W)(p|P)(d|D))|((r|R)(t|T)(f|F)))$"

I don't understand the "=^([a-zA-Z].*|[0-9].*)\."
Can someone please help me translate this?

Thank you!
0
Comment
Question by:ocdc
  • 2
2 Comments
 
LVL 35

Assisted Solution

by:Terry Woods
Terry Woods earned 500 total points
ID: 37803752
^([a-zA-Z].*|[0-9].*)\.
means:
^  match the start of the string (or line, in multiline mode)
( start a capturing group
[a-zA-Z] match any one alphabetic character
.* match any number of any characters except newline
| logical OR applying within the capturing group
[0-9] match one digit
.* match any number of any characters except newline
) end the capturing group
\. match a . character

To summarise:

It looks like you're matching filenames. That part of the pattern will match and capture the entire filename (and path, if there) up to the extension as long as it starts with a letter or number, except it won't include the . character in the captured group.
0
 
LVL 35

Accepted Solution

by:
Terry Woods earned 500 total points
ID: 37803777
Examples:

For the string:
C:\foo\rhubarb\myfile.pdf
The part of the pattern you're asking about would capture:
C:\foo\rhubarb\myfile
but would match
C:\foo\rhubarb\myfile.

For the string:
123/456/rhubarb/myfile.pdf
The part of the pattern you're asking about would capture:
123/456/rhubarb/myfile
but would match
123/456/rhubarb/myfile.

For the string:
_somedir/rhubarb/myfile.pdf
The pattern would fail to match, as it doesn't start with a number or letter.
0

Featured Post

DevOps Toolchain Recommendations

Read this Gartner Research Note and discover how your IT organization can automate and optimize DevOps processes using a toolchain architecture.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Browsers only know CSS so your awesome SASS code needs to be translated into normal CSS. Here I'll try to explain what you should aim for in order to take full advantage of SASS.
Have you tried to learn about Unicode, UTF-8, and multibyte text encoding and all the articles are just too "academic" or too technical? This article aims to make the whole topic easy for just about anyone to understand.
Learn how to match and substitute tagged data using PHP regular expressions. Demonstrated on Windows 7, but also applies to other operating systems. Demonstrated technique applies to PHP (all versions) and Firefox, but very similar techniques will w…
The viewer will learn how to look for a specific file type in a local or remote server directory using PHP.

803 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question