How to know the extension of documents/files?

Question

I need to know the extension of different documents and depending of the extensions take some decisions within my code: for example I can have this FileNames:

commands to save.docx Old Word.doc rel.txt test.pdf

I know that using the Contains() method that comes with Linq I could do something but I'm afraid that using Contains() it will take a .doc extension even if is a .docx extension because .doc is a substring of .docx

I think that a better approach would be maybe a regular expression for this... Any suggestion?

I've done something like this but maybe a RegEx should be a better approach:

if (fileName.Contains(".pdf"))
{
    Response.AddHeader("Content-Type", "application/pdf; Content-Disposition, inline" + fileName);
}

score 4 · Answer 1 · edited May 23 '17 at 11:48

4

You will find what you seek here, using Path.GetExtension

edited May 23 '17 at 11:48

Community

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answered Oct 31 '16 at 22:53

Jonathan M

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Links are not good naswers, put relevant code to the question. – mybirthname Oct 31 '16 at 23:12
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@mybirthname it shouldn't have been an answer at all, this should have been marked as duplicate, and in general, links to relevant information should be added with a quote, doesn't mean there shouldn't be a link. – Dispersia Oct 31 '16 at 23:26
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@Dispersia Indeed. Fixed :) – Ivan Stoev Oct 31 '16 at 23:44

score 1 · Accepted Answer · answered Oct 31 '16 at 22:54

You may use the MimeMapping.GetMimeMapping method the mime type of the document. With that,you do not really need to get the file extension and write those if condition for all the different types.

var fileName = Path.GetFileName("SomeFileNameWithLongPath.pdf");
string mimeType= MimeMapping.GetMimeMapping(fileName );

If you really want the extension, you can use the Path.GetExtension method

var extension = Path.GetExtension("SomeFileNameWithLongPath.pdf");

How to know the extension of documents/files?

2 Answers2