MicrosoftCommon Object File Format
application/octet-stream
Magic Bytes
Offset: 0
4C 41 3A
Microsoft Common Object File Format is a specification for executable and object code files developed by Microsoft for use on Windows operating systems. These files serve as intermediate products of the compilation process, containing machine code that linkers aggregate into final executable programs or libraries. As static binary data intended for build-time processing, the format is considered safe, though it remains a legacy standard largely superseded by the modern Portable Executable format.
Validation Code
How to validate .obj files in Python
Python
def is_obj(file_path: str) -> bool:
"""Check if file is a valid OBJ by magic bytes."""
signature = bytes([0x4C, 0x41, 0x3A])
with open(file_path, "rb") as f:
return f.read(3) == signatureHow to validate .obj files in Node.js
Node.js
function isOBJ(buffer: Buffer): boolean {
const signature = Buffer.from([0x4C, 0x41, 0x3A]);
return buffer.subarray(0, 3).equals(signature);
}
Go
func IsOBJ(data []byte) bool {
signature := []byte{0x4C, 0x41, 0x3A}
if len(data) < 3 {
return false
}
return bytes.Equal(data[:3], signature)
}API Endpoint
GET
/api/v1/obj
curl https://filesignature.org/api/v1/obj