What is MIME type "text/x-csrc"?

A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.

text/x-csrc is a MIME type indicating plain text files that follow C language syntax rules. It is used by tools and editors to recognize source code files, enabling features like syntax highlighting and proper formatting.

This classification tells applications that the file’s content is code, not binary data. The “x-” prefix marks it as experimental or non-standard but is widely adopted in practice.

Syntax Highlighting: Editors use it to apply C-based color schemes and formatting.
Source Code Recognition: It signals that the file contains code written in C or similar languages.
Toolchain Integration: Compilers and development tools treat these files as editable text.

Files using this MIME type span many extensions. Typical examples include C files, H header files, as well as files specific to variants like HC (HolyC), MC (Monkey C), GSC, and ISPC. Other extensions—such as PM, XPM, XBM, CL, OPENCL, and others—are also managed under this umbrella when their syntax adheres to C-style rules.

This MIME type is crucial for development environments because it ensures that files with C-like code are handled correctly, even if they come from different programming traditions or domains. For further reading on MIME types, visit Wikipedia: MIME.

Associated file extensions

.h, .hc, .mc, .gsc, .pm, .xpm, .csc, .d, .c, .xbm, .xs, .nss, .idc, .cl, .xc, .upc, .cats, .gsh, .h.in, .ispc, .opencl, .smithy

Usage Examples

HTTP Header

When serving content with this MIME type, set the Content-Type header:


    Content-Type: text/x-csrc

HTML

In HTML, you can specify the MIME type in various elements:


    <a href="file.dat" type="text/x-csrc">Download file</a>

Server-side (Node.js)

Setting the Content-Type header in Node.js:


    const http = require('http');    
    
    http.createServer((req, res) => {    
      res.setHeader('Content-Type', 'text/x-csrc');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.h, .hc, .mc, .gsc, .pm, .xpm, .csc, .d, .c, .xbm, .xs, .nss, .idc, .cl, .xc, .upc, .cats, .gsh, .h.in, .ispc, .opencl, .smithy

FAQs

What is the text/x-csrc MIME type used for?

text/x-csrc is the media type used to identify source code written in the C programming language. It tells web servers, browsers, and text editors that the file contains plain text following C syntax rules, enabling features like syntax highlighting and code formatting.

Which file extensions are associated with text/x-csrc?

The most common extension is .c, but it covers many C-like formats. This includes header files like .h, OpenCL files (.cl), and even C-based image formats like .xpm and .xbm.

Why are image formats like XPM and XBM linked to a text MIME type?

Unlike binary images (like JPEG or PNG), XPM (X PixMap) and XBM (X BitMap) files define images using valid C code arrays. Since these files are technically plain text source code that can be compiled into a program, they are correctly identified as text/x-csrc.

How do I configure Apache to serve C files with this MIME type?

You can ensure your Apache server serves C source files with the correct header by adding a directive to your .htaccess or httpd.conf file. Use the line: AddType text/x-csrc .c .h .cl.

What is the difference between text/x-csrc and text/x-c++src?

While both types represent source code, text/x-csrc is specific to the C language, whereas text/x-c++src is used for C++ files (e.g., .cpp). Although the syntaxes are similar, distinguishing them allows editors to apply the correct keywords and compiler rules for each language.

Why does the MIME type start with "x-"?

The x- prefix indicates that this MIME type is a non-standard or experimental type not officially registered with the IANA when it was created. However, text/x-csrc has become the de facto standard for C source code across the web and operating systems.

Can web browsers execute files served as text/x-csrc?

No, web browsers cannot execute C source code directly. If a browser navigates to a file served as text/x-csrc, it will typically display the code as plain text. To run the code, it must be compiled into a binary executable using a compiler like GCC or Clang.

General FAQ

What is a MIME type?

A MIME (Multipurpose Internet Mail Extensions) type is a standard that indicates the nature and format of a document, file, or assortment of bytes. MIME types are defined and standardized in IETF's RFC 6838.

MIME types are important because they help browsers and servers understand how to process a file. When a browser receives a file from a server, it uses the MIME type to determine how to display or handle the content, whether it's an image to display, a PDF to open in a viewer, or a video to play.

MIME types consist of a type and a subtype, separated by a slash (e.g., text/html, image/jpeg, application/pdf). Some MIME types also include optional parameters.

How do I find the MIME type for a file?

You can check the file extension or use a file identification tool such as file --mime-type on the command line. Many programming languages also provide libraries to detect MIME types.

Why are multiple MIME types listed for one extension?

Different applications and historical conventions may use alternative MIME identifiers for the same kind of file. Showing them all helps ensure compatibility across systems.