Regular Expression to find files with various extensions like-ASPX,ASCX,.js,.rpt,.xml

Question

Is there any way to write a RegEx which can be used to find files with different Extensions.

Answer 1

I'm sure there is, but the question you should be asking is "What's the best way to find files which have specific extensions?".

Regular expressions are not the best answer to every question.

I would suggest just getting a list of all files and passing them into a function like IsThisFileOneIWant(fileName,extensionList). That's far easier than trying to shoehorn the use of regular expressions into your problem.

Something like this should do it:

function IsThisFileOneIWant(fileName,extensionList):
    for each extension in extensionList:
        if fileName.endsWith (extension):
            return true
    return false

Done in pseudo-code since it should be simple enough to turn into any other language.

If you must have a regex, it's going to look something like (based on the values in your question):

"ASPX$|ASCX$|\.js$|\.rpt$|\.xml$"

but it depends entirely on the RE engine that you want to use. For example, here's the output from an egrep command in my work directory:

pax@paxbox1:~/work$ ls -1 | egrep '\.sh$|\.c$'
  backup0.sh
  backup1.sh
  eclipse.sh
  monbt.sh
  qq.c
  qq.sh
  xx yy.sh

Answer 2

Assuming you have a list of files and you are looking for .pdf, .chm and .doc, you can check it with:

\.pdf$|\.chm$|\.doc$

Regex above should work if you will check it against single filenames.