Is there a function to extract the extension from a filename?

Extracting extension from filename in Python

On GitHub, several projects have `README.md` files. It seems like a simple format file to express text and pictures. 

I guess there is an editor or syntax explanation somewhere.

Where can I find an introduction to `.md` files?

What file uses .md extension and how should I edit them?

This is a question you can read everywhere on the web with various answers:

    $ext = end(explode(&#39;.&#39;, $filename));
    $ext = substr(strrchr($filename, &#39;.&#39;), 1);
    $ext = substr($filename, strrpos($filename, &#39;.&#39;) + 1);
    $ext = preg_replace(&#39;/^.*\.([^.]+)$/D&#39;, &#39;$1&#39;, $filename);

    $exts = split(&quot;[/\\.]&quot;, $filename);
    $n    = count($exts)-1;
    $ext  = $exts[$n];

etc.

However, there is always &quot;the best way&quot; and it should be on Stack Overflow.


How to get a file&#39;s extension in PHP?

 See code: 

    var file1 = &quot;50.xsl&quot;;
    var file2 = &quot;30.doc&quot;;
    getFileExtension(file1); //returns xsl
    getFileExtension(file2); //returns doc

    function getFileExtension(filename) {
        /*TODO*/
    }




How can I get file extensions with JavaScript?

I wish to get the file extension of an image I am uploading, but I just get an array back. 

    $userfile_name = $_FILES[&#39;image&#39;][&#39;name&#39;];
    $userfile_extn = explode(&quot;.&quot;, strtolower($_FILES[&#39;image&#39;][&#39;name&#39;]));

Is there a way to just get the extension itself?


How to get the file extension in PHP?

On a Linux machine I would like to traverse a folder hierarchy and get a list of all of the distinct file extensions within it.

What would be the best way to achieve this from a shell?


How can I find all of the distinct file extensions in a folder hierarchy?

I program in WPF C#.  I have e.g. the following path:
```
C:\Program Files\hello.txt
```
and I want to extract **`hello`** from it. 

The path is a `string` retrieved from a database.  Currently I&#39;m using the following code to split the path by `&#39;\&#39;` and then split again by `&#39;.&#39;`:
```c#
string path = &quot;C:\\Program Files\\hello.txt&quot;;
string[] pathArr = path.Split(&#39;\\&#39;);
string[] fileArr = pathArr.Last().Split(&#39;.&#39;);
string fileName = fileArr.Last().ToString();
```
It works, but I believe there should be shorter and smarter solution to that. Any idea?

Given a filesystem path, is there a shorter way to extract the filename without its extension?

I often use `JPEG` images, and I have noticed that there are two very similar file extensions: `.jpg`, which my mobile&#39;s camera and the _Preview_ application use, and `.jpeg`, with which _Image Capture_ saves the images from scanning with my _Canon MX455_ printer. _LaTeX_ doesn&#39;t seem to distinguish, as I gave it a `.jpeg` with the extension changed to `.jpg` and the result seems to be the same as if it had been a `.jpg` right from the start. I have wondered what the difference between the two is. I have come across [this question](https://stackoverflow.com/questions/419584/what-is-the-difference-between-jpg-jpeg-png-bmp-gif-tiff-i), and will certainly read through it, though at the moment I&#39;m slightly out of time. However, from what I saw giving it a quick look, it seems not to distinguish the two extensions. In fact, it seems the file type&#39;s name is `JPEG` and the file extension is `.jpg`:

&gt;JPEG (or JPG, for the file extension; Joint Photographic Experts Group)

(excerpted from the first answer there). So is there any big difference between the two extensions? And if so, what is it?

JPG vs. JPEG image formats

I&#39;m wondering what the difference between .phtml and .php files is, and when to use one over the other.

What is phtml, and when should I use a .phtml extension rather than .php?

I&#39;m working on a certain program where I need to do different things depending on the extension of the file. Could I just use this?


    if m == *.mp3
       ...
    elif m == *.flac
       ...

How can I check the extension of a file?

What is the difference between the `.htm` and `.html` file extension?

Why there are two of them?

Which is correct?

Should you use .htm or .html file extension? What is the difference, and which file is correct?

Since I started learning Objective-C and Cocoa, I&#39;ve been wondering why they have chosen the extension .m for the implementation files - was it supposed to mean something, or was it just a random letter?


Why do Objective-C files use the .m extension?

Is there an option to restrict `git diff` to a given set of file extensions?

How to filter git diff based on file extensions?

In my web application (asp.net,c#) I am uploading video file in a page but I want to upload only flv videos. How can I restrict when I upload other extension videos?

How to find the extension of a file in C#?

I have a few directories and sub-directories containing files with no file extension. I want to add `.jpg` to all the files contained within these directories. I&#39;ve seen bash scripts for changing the file extension but not for just adding one. It also needs to be recursive, can someone help please?


recursively add file extension to all files

I&#39;d like to find all *.html files in src folder and all its sub folders using nodejs. What is the best way to do it? 

    var folder = &#39;/project1/src&#39;;
    var extension = &#39;html&#39;;
    var cb = function(err, results) {
       // results is an array of the files with path relative to the folder
       console.log(results);

    }
    // This function is what I am looking for. It has to recursively traverse all sub folders. 
    findFiles(folder, extension, cb);

I think a lot developers should have great and tested solution and it is better to use it than writing one myself. 




find files by extension, *.html under a folder in nodejs

Suppose from `index.py` with CGI, I have post file `foo.fasta` to display file. I want to change `foo.fasta`&#39;s file extension to be `foo.aln` in display file. How can I do it?



Changing file extension in Python

I know that, if I wanted to grep for a pattern only on files with certain extensions, I could do this:

    // searches recursively and matches case insensitively in only javascript files
    // for &quot;res&quot; from the current directory
    grep -iIr --include=*.js res ./

I&#39;ve been trying to search for a way to do this via git grep as well (to take advantage of git grep&#39;s speed from the indexes it stores with its tree), but to no avail. I saw [here][1] that excluding certain file types is not possible.


  [1]: http://git.661346.n2.nabble.com/git-grep-while-excluding-files-in-a-blacklist-td7195648.html

git grep by file extensions

I&#39;ve seen `.S` files in various projects such as in the Linux Kernel, FreeBSD kernel, or in some other projects.  What do these files do and why can&#39;t we have `.c` files instead ? 

What are .S files?

I need to programatically distinguish between Jinja template files, other template files (such as ERB), and template-less plain text files.

According to [Jinja documentation]:

&gt; A Jinja template doesn’t need to have a specific extension: .html, .xml, or any other extension is just fine.

But what should I use when an explicit extension is required? `.py` is misleading, and any search including the words &quot;jinja&quot; and &quot;extension&quot; are badly searchwashed by discussion around [Jinja Extensions].

I could easily dictate a project-wide convention (`.jnj` or `.ja` come to mind) but this is for open source so I don&#39;t want to buck the trend if there&#39;s already established practice somewhere.

---
**EDIT 1:** Again, I understand that the Jinja project &amp;mdash; purposefully &amp;mdash; does not define a default file extension. I&#39;m asking if there are any unofficial conventions that have emerged for circumstances where one is desired for some project-specific reason.

---
**EDIT 2:** Clarification: This is not for HTML content.

[jinja documentation]: http://jinja.pocoo.org/docs/dev/templates/
[jinja extensions]: http://jinja.pocoo.org/docs/dev/extensions/

Is there an idiomatic file extension for Jinja templates?

Given a string `&quot;filename.conf&quot;`, how to I verify the extension part?

I need a cross platform solution.

How to get file extension from string in C++

I am seeing some strange behavior with my application and the state of its database file after running some tests that close the database, delete it, and replace it with a test fixture.  When I examine the database file with a tool on my debugging PC, it doesn&#39;t match what the application itself seems to be reporting.  It&#39;s possible that this strange behavior is related to [this bug][1].

I noticed that there are two files with the same base name as the database (with the normal `.db` extension.)  The file extensions are `.db-shm` and `.db-wal`, and each is newer than the `.db` file&#39;s timestamp.  

I assume that these are some type of temporary files.  However, I am wondering if the application is terminated, shouldn&#39;t they be deleted?  More importantly, I assume whatever data is stored in them is updated inside the `.db` file before the application is terminated by the operating system.  Is this correct?


  [1]: http://code.google.com/p/android/issues/detail?id=13727

What are the .db-shm and .db-wal extensions in Sqlite databases?

Usually a C# project has a .csproj file associated with it. What is that file for? What data does it contain? 

What does the .csproj file do?

While searching for an implementation of the Barnsley&#39;s Fern fractal I came across a implementation that has .pde extension. Which programming language uses this extension?

[Implementation Page][1]


  [1]: http://www.openprocessing.org/visuals/?visualID=198

Which language uses .pde extension?

I have a directory full of files with one extension (.txt in this case) that I want to automatically convert to another extension (.md).

Is there an easy terminal one-liner I can use to convert all of the files in this directory to a different file extension?

Or do I need to write a script with a regular expression?



Changing file extensions for all files in a directory on OS X

I have seen `.gnu`, `.plt`, and `.gplot` as file extensions for gnuplot scripts.

I know Linux doesn&#39;t care about file extensions, but what extension most universally declares to human beings &quot;*I am a gnuplot script!*&quot;?

Is there a standard file extension for gnuplot files?

Just wondering which programming languages is used on the web pages with the extension &quot;.do&quot;


Which programming language has extension .do

    public string ContructOrganizationNameLogo(HttpPostedFileBase upload, string OrganizationName, int OrganizationID,string LangName)
        {
             var UploadedfileName = Path.GetFileName(upload.FileName);
            string type = upload.ContentType;
        }

I want to get the extension of the file to dynamically generate the name of the file.One way i will use to split the type. but can i use HttpPostedFileBase object to get the extension in the clean way?

asp.net mvc HttpPostedFileBase getting file extension

Is there a resource that lists ALL the mimeTypes in existence?

I have found a few places with under 1000 mimeTypes, but then they still don&#39;t include common ones like .rar, .fla, .rb, .docx!

Does anyone have a COMPLETE list of mimetypes?  Not down to the most obsure &quot;company-only&quot; ones, but at least all of the ones we might use.

Also, I&#39;m looking for a list that maps file extensions to mimeTypes.

List of ALL MimeTypes on the Planet, mapped to File Extensions?

How can I extract the extension of a file given a file path as a character?  I know I can do this via regular expression `regexpr(&quot;\\.([[:alnum:]]+)$&quot;, x)`, but wondering if there&#39;s a built-in function to deal with this?

Extract file extension from file path

I saw some examples creating the JSF pages with `.jsp` extension, other examples creating them with `.xhtml` extension, and other examples choose `.jsf`.
I just would like to know what the difference is between above extensions when working with JSF pages, and how to choose the appropriate extension?

What is the difference between creating JSF pages with .jsp or .xhtml or .jsf extension

I want to get a MIME Content-Type from a given extension (preferably without accessing the physical file). I have seen some questions about this and the methods described to perform this can be resumed in:

 1. Use [registry information][1].
 2. Use [urlmon.dll&#39;s FindMimeFromData][2].
 3. Use [IIS information][3].
 4. Roll your own MIME mapping function. Based on [this table][4], for example.

I&#39;ve been using no.1 for some time but I realized that the information provided by the registry is not consistent and depends on the software installed on the machine. Some extensions, like .zip don&#39;t use to have a Content-Type specified.

Solution no.2 forces me to have the file on disk in order to read the first bytes, which is something slow but may get good results.

The third method is based on Directory Services and all that stuff, which is something I don&#39;t like much because I have to add COM references and I&#39;m not sure it&#39;s consistent between IIS6 and IIS7. Also, I don&#39;t know the performance of this method.

Finally, I didn&#39;t want to use my own table but at the end seems the best option if I want a decent performance and consistency of the results between platforms (even Mono).

Do you think there&#39;s a better option than using my own table or one of other described methods are better? What&#39;s your experience?

  [1]: https://stackoverflow.com/questions/1029740/get-a-mime-from-an-extention/1029796#1029796
  [2]: https://stackoverflow.com/questions/58510/in-c-how-can-you-find-the-mime-type-of-a-file-based-on-the-file-signature-not-th/58570#58570
  [3]: https://stackoverflow.com/questions/174888/asp-net-iis6-how-to-search-the-servers-mime-map/174988#174988
  [4]: http://svn.apache.org/repos/asf/httpd/httpd/trunk/docs/conf/mime.types

File extensions and MIME Types in .NET

When I traced my reference MATLAB script, I found files with the `.mat` extension. My questions are:

 1. What is the difference between `.mat` and `.m` files?
 2. How does one open files with the `.mat` extension?


What is the difference between .m and .mat files in MATLAB

Say I have something like this:

    new File(&quot;test&quot;).eachFile() { file-&gt;  
    println file.getName()  
    }

This prints the full filename of every file in the `test` directory.  Is there a Groovy way to get the filename without any extension?  (Or am I back in regex land?)

Does groovy have an easy way to get a filename without the extension?

I have a base64 encoded image returned from a service and it looks like this:


    /9j/4AAQSkZJRgABAQEASABIAAD/4Yp2aHR0cDovL25zLmFkb2JlLmNvbS94YXAvMS4wLwA8P3hwYWNrZXQgYmVnaW49Iu+7vyIgaWQ9Ilc1TTBNcENlaGlIenJlU3pOVGN6a2M5ZCI/Pgo8eDp4bXBtZXRhIHhtbG5zOng9ImFkb2JlOm5zOm1ldGEvIiB4OnhtcHRrPSJBZG9iZSBYTVAgQ29yZSA0LjEtYzAzNiA0Ni4yNzcwOTIsIEZyaSBGZWIgMjMgMjAwNyAxNDoxNjoxOCAgICAgICAgIj4KICAgPHJkZjpSREYgeG1.... etc

How can i detect / check the image extension?





All File Extension Solutions on Gang of Coders

Total of 35 File Extension Solutions