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Visual Basic User-defined Control file (.ctl)

.ctl file signature | application/octet-stream

Visual Basic User-defined Control file

Safe

Magic Bytes

Offset 0
56 45 52 53 49 4F 4E 20

Sources: Gary Kessler

Extension

.ctl

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .ctl files in Python

Python 
def is_ctl(file_path: str) -> bool:
    """Check if file is a valid CTL by magic bytes."""
    signature = bytes([0x56, 0x45, 0x52, 0x53, 0x49, 0x4F, 0x4E, 0x20])
    with open(file_path, "rb") as f:
        return f.read(8) == signature

How to validate .ctl files in Node.js

Node.js 
function isCTL(buffer: Buffer): boolean {
  const signature = Buffer.from([0x56, 0x45, 0x52, 0x53, 0x49, 0x4F, 0x4E, 0x20]);
  return buffer.subarray(0, 8).equals(signature);
}

How to validate .ctl files in Go

Go 
func IsCTL(data []byte) bool {
    signature := []byte{0x56, 0x45, 0x52, 0x53, 0x49, 0x4F, 0x4E, 0x20}
    if len(data) < 8 {
        return false
    }
    return bytes.Equal(data[:8], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .ctl file?

A .ctl file is a Visual Basic User-defined Control file file. Visual Basic User-defined Control file

What are the magic bytes for .ctl files?

The magic bytes for Visual Basic User-defined Control file files are 56 45 52 53 49 4F 4E 20 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .ctl file?

To validate a .ctl file, read the first bytes of the file and compare them against the known magic bytes (56 45 52 53 49 4F 4E 20) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .ctl files?

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

Is it safe to open .ctl files?

Visual Basic User-defined Control file (.ctl) 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.