There seems to be a lot of questions asking for regex to detect a CSV file type, but none for javascript.

Given that a regular expression for images looks like /^image\/(gif|jpeg|png)$/, does anyone know what the same would look like for CSV?

Edit To be a little more clear, looking for both a "how-to" to regex check if file is a CSV and the mon extensions associated. Thanks!

There seems to be a lot of questions asking for regex to detect a CSV file type, but none for javascript.

Given that a regular expression for images looks like /^image\/(gif|jpeg|png)$/, does anyone know what the same would look like for CSV?

Edit To be a little more clear, looking for both a "how-to" to regex check if file is a CSV and the mon extensions associated. Thanks!

• javascript
• regex

• 1 Note that checking for file extension is not sufficient to securely identify the file type; it varies by platform but generally it's possible to give any sort of file any name with any extension. – Pointy Commented Jun 22, 2012 at 21:19
• Are you asking (1) what are the possible extensions for CSV files, or (2) how do you create a regular expression to look for them? – JW. Commented Jun 22, 2012 at 21:19
• My bad I guess I was a little vague, basically I'm asking both. How to create a robust regular expression that can handle most mon file types for CSV (looks like only 1...) – crockpotveggies Commented Jun 22, 2012 at 21:20
• If you're just looking to see if a URL represents a csv file, then a Regex is fine; if you want to confirm that the file associated with that file is actually a CSV, you'll need to do more work, probably checking the mime-type – jackwanders Commented Jun 22, 2012 at 21:23
• Understood, I'll probably use a little of both to 1) check the extension using @tskuzzy's solution on the client and 2) check MIME-type server-side. Thanks for reminding me of MIME-type ;) – crockpotveggies Commented Jun 22, 2012 at 21:27

1 Answer 1

The CSV file extension is typically .csv. So try matching against that:

.+(\.csv)$