Regex for a valid filepath filename extension

David Smith

I am looking for a regex that validates a couple of things.

1.Validate is the string is a valid filepath.
2. Validate if the extension has a '.xml' extension.

12 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes13y ago
Accepted answer
The reason it doesn't work is because the file path contains some upper case letters and the regex you're using only allows for lower case letters.

However, the regex in my first post does allow for upper and lower case letters and works fine in this case:

string regExp = @"^(?:[A-Za-z]\:|\\)(\\[a-zA-Z_\-\s0-9\.]+)+\.xml$";
0
David Smith13y ago
Thanks vuples. This works.
0
David Smith13y ago
The regex is false when I do this below. It goes into the else case which is false because that's a valid filename path extension. Something is wrong with the regex string probably

var regExp = @"^(?:[\w]\:|\\)(\\[a-z_\-\s0-9\.]+)+\.(xml|)$";
          string fileN = @"C:\Temp\Run5.xml";
          Regex regex = new Regex(regExp);

          if (regex.IsMatch(fileN))
{
}
else

{

}
0
Iftikar Hussain13y ago
Vulpes

Yes you are right, it should be like this

var regExp = @"^(?:[A-Za-z]\:|\\)(\\[a-z_\-\s0-9\.]+)+\.(xml)$";
var fileName = TxtBxFirstName.Text;
Regex regex = new Regex(regExp);
if (regex.IsMatch(fileName))
{
MessageBox.Show("Valid File");
}
else
{
MessageBox.Show("InValid File");
}

Regards,
Iftikar
0
Vulpes13y ago
Iftikar,

That would validate some invalid file paths such as this one:

2:\my files\vulpes.xml

As the drive needs to be a letter, the \w needs to be replaced by a-z and A-Z also needs including if you want it to be case insensitive, as in my own effort.
0
Iftikar Hussain13y ago
sorry, try this

var regExp = @"^(?:[\w]\:|\\)(\\[a-z_\-\s0-9\.]+)+\.(xml)$";
var fileName = TxtBxFirstName.Text;
Regex regex = new Regex(regExp);
if (regex.IsMatch(fileName))
{
MessageBox.Show("Valid File");
}
else
{
MessageBox.Show("InValid File");
}

Regards,
Iftikar
0
Iftikar Hussain13y ago
What is your file path and file name? Can you give me example?

Regards,
Iftikar
0
David Smith13y ago
I tried this earlier. This did not work. I am going to post my code later.

var regExp = @"^(?:[\w]\:|\\)(\\[a-z_\-\s0-9\.]+)+\.(xls|xlsx)$";
var fileName = TxtBxFirstName.Text;
Regex regex = new Regex(regExp);
if (regex.IsMatch(fileName))
{
MessageBox.Show("Valid File");
}
else
{
MessageBox.Show("InValid File");
}
0
Sanjeeb Lenka13y ago
var regExp = @"^(?:[\w]\:|\\)(\\[a-z_\-\s0-9\.]+)+\.(txt|gif|pdf|doc|docx|xls|xlsx|xml)$";

for more detail follow this link

http://www.codeproject.com/Tips/216238/Regular-Expression-to-Validate-File-Path-and-Exten
0
Iftikar Hussain13y ago
Hi,
Try this

var regExp = @"^(?:[\w]\:|\\)(\\[a-z_\-\s0-9\.]+)+\.(xls|xlsx)$";
var fileName = TxtBxFirstName.Text;
Regex regex = new Regex(regExp);
if (regex.IsMatch(fileName))
{
MessageBox.Show("Valid File");
}
else
{
MessageBox.Show("InValid File");
}

Matches Pattern
-------------------
\\100.100.10.10\Test\dummy.xls
\\100.100.10.10\Test\Test.2\dummy.xlsx
C:\Test folder\Test Test.xls
C:\Test-folder\Test_folder\Test.v2.xls

Non-Matched Pattern
--------------------------
\\100.100.10.10\Test\fi
C:\Test folder\Test_folder\.xls
C:\Test folder\\Test_folder\dummy.xls

Regards,
Iftikar
0
Jignesh Trivedi13y ago
hi,
Please refer following link it might help you
http://www.codeproject.com/Tips/216238/Regular-Expression-to-Validate-File-Path-and-Exten
http://www.coderanch.com/t/551777/java/java/Validating-file-path-regex
0
Vulpes13y ago
Try this:

string regExp = @"^(?:[A-Za-z]\:|\\)(\\[a-zA-Z_\-\s0-9\.]+)+\.xml$";
0