Recently, I was looking for a regular expression to validate a file path and extension. I found several of them on Google, but none of them fit my requirement. So I decided to put together a version that suits my need. Here is the Regular Expression to validate the file path and extension and it is compatible with JavaScript and ASP.NET. I hope someone will find this information useful and that it will make your programming job easier.

Hide Copy Code ^(?:[\w]:|\)(\[a-z_-\s0-9.]+)+.(txt|gif|pdf|doc|docx|xls|xlsx)$ Explanation Hide Copy Code ^(?:[\w]:|\) -- Begin with x:\ or \

[a-z_-\s0-9.] -- valid characters are a-z| 0-9|-|.|_ (you can add more)

(txt|gif|pdf|doc|docx|xls|xlsx) -- Valid extension (you can add more) Matches Hide Copy Code \192.168.0.1\folder\file.pdf \192.168.0.1\my folder\folder.2\file.gif c:\my folder\abc abc.docx c:\my-folder\another_folder\abc.v2.docx Non-Matches Hide Copy Code \192.168.0.1\folder\fi<le.pdf \192.168.0.1\folder\file.pdf \192.168.0.1\my folder\folder.2.gif c:\my folder\another_folder.docx c:\my folder\another_folder\abc.docx c:\my folder\another_folder\ab*c.v2.docx c:\my?folder\another_folder\abc.v2.docx file.xls