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PEN (.pen)

.pen file signature | text/plain

Safe

Magic Bytes

Offset 0
54 68 69 73 20 69 73 20 54 65 58 2C

Sources: Apache Tika

All Known Signatures

8 signature variants are documented for .pen files across multiple sources.

Hex Signature Offset Sources
54 68 69 73 20 69 73 20 54 65 58 2C 0 Apache Tika
54 68 69 73 20 69 73 20 4D 45 54 41 46 4F 4E 54 2C 0 Apache Tika
2F 2A 0 Apache Tika
2F 2F 0 Apache Tika
3B 3B 0 Apache Tika
FE FF 0 Apache Tika
FF FE 0 Apache Tika
EF BB BF 0 Apache Tika

Extension

.pen

MIME Type

text/plain

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .pen files in Python

Python 
def is_pen(file_path: str) -> bool:
    """Check if file is a valid PEN by magic bytes."""
    signature = bytes([0x54, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x54, 0x65, 0x58, 0x2C])
    with open(file_path, "rb") as f:
        return f.read(12) == signature

How to validate .pen files in Node.js

Node.js 
function isPEN(buffer: Buffer): boolean {
  const signature = Buffer.from([0x54, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x54, 0x65, 0x58, 0x2C]);
  return buffer.subarray(0, 12).equals(signature);
}

How to validate .pen files in Go

Go 
func IsPEN(data []byte) bool {
    signature := []byte{0x54, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x54, 0x65, 0x58, 0x2C}
    if len(data) < 12 {
        return false
    }
    return bytes.Equal(data[:12], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .pen file?

A .pen file is a PEN file.

What are the magic bytes for .pen files?

The magic bytes for PEN files are 54 68 69 73 20 69 73 20 54 65 58 2C at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .pen file?

To validate a .pen file, read the first bytes of the file and compare them against the known magic bytes (54 68 69 73 20 69 73 20 54 65 58 2C) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .pen files?

The primary MIME type for .pen files is text/plain.

Is it safe to open .pen files?

PEN (.pen) 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.