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DIR (.dir)

.dir file signature | application/octet-stream

Macromedia Directorfile format[86][84][85]

Safe

Magic Bytes

Offset 0
52 49 46 58 4D 56 39 33

Sources: Wikipedia

Extension

.dir

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .dir files in Python

Python 
def is_dir(file_path: str) -> bool:
    """Check if file is a valid DIR by magic bytes."""
    signature = bytes([0x52, 0x49, 0x46, 0x58, 0x4D, 0x56, 0x39, 0x33])
    with open(file_path, "rb") as f:
        return f.read(8) == signature

How to validate .dir files in Node.js

Node.js 
function isDIR(buffer: Buffer): boolean {
  const signature = Buffer.from([0x52, 0x49, 0x46, 0x58, 0x4D, 0x56, 0x39, 0x33]);
  return buffer.subarray(0, 8).equals(signature);
}

How to validate .dir files in Go

Go 
func IsDIR(data []byte) bool {
    signature := []byte{0x52, 0x49, 0x46, 0x58, 0x4D, 0x56, 0x39, 0x33}
    if len(data) < 8 {
        return false
    }
    return bytes.Equal(data[:8], signature)
}

API Endpoint

GET /api/v1/dir
curl https://filesignature.org/api/v1/dir

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .dir file?

A .dir file is a DIR file. Macromedia Directorfile format[86][84][85]

What are the magic bytes for .dir files?

The magic bytes for DIR files are 52 49 46 58 4D 56 39 33 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .dir file?

To validate a .dir file, read the first bytes of the file and compare them against the known magic bytes (52 49 46 58 4D 56 39 33) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .dir files?

There is no officially registered MIME type for .dir files. Systems typically use application/octet-stream as a generic fallback when handling this format.

Is it safe to open .dir files?

DIR (.dir) files are generally safe to open. They are classified as low risk because they primarily contain data rather than executable code. However, always ensure files come from a trusted source.