Unix archiver (.lib)

.lib file signature | application/octet-stream

Unix archiver (ar) files and Microsoft Program LibraryCommon Object File Format (COFF)

Safe

Magic Bytes

Offset 0


              21 3C 61 72 63 68 3E 0A

Sources: Gary Kessler

Extension

.lib

MIME Type

application/octet-stream

Byte Offset

Risk Level

Safe

Validation Code

How to validate .lib files in Python

Python

def is_lib(file_path: str) -> bool:
    """Check if file is a valid LIB by magic bytes."""
    signature = bytes([0x21, 0x3C, 0x61, 0x72, 0x63, 0x68, 0x3E, 0x0A])
    with open(file_path, "rb") as f:
        return f.read(8) == signature

How to validate .lib files in Node.js

Node.js

function isLIB(buffer: Buffer): boolean {
  const signature = Buffer.from([0x21, 0x3C, 0x61, 0x72, 0x63, 0x68, 0x3E, 0x0A]);
  return buffer.subarray(0, 8).equals(signature);
}

How to validate .lib files in Go

func IsLIB(data []byte) bool {
    signature := []byte{0x21, 0x3C, 0x61, 0x72, 0x63, 0x68, 0x3E, 0x0A}
    if len(data) < 8 {
        return false
    }
    return bytes.Equal(data[:8], signature)
}

API Endpoint

GET /api/v1/lib


              curl https://filesignature.org/api/v1/lib

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .lib file?

A .lib file is a Unix archiver file. Unix archiver (ar) files and Microsoft Program LibraryCommon Object File Format (COFF)

What are the magic bytes for .lib files?

The magic bytes for Unix archiver files are 21 3C 61 72 63 68 3E 0A at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .lib file?

To validate a .lib file, read the first bytes of the file and compare them against the known magic bytes (21 3C 61 72 63 68 3E 0A) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .lib files?

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

Is it safe to open .lib files?

Unix archiver (.lib) 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.