Unix archiver magic bytes (.lib)
.lib file signature: 21 3C 61 72 63 68 3E 0A | application/octet-stream
The Unix archiver (ar) format is a legacy archive file format originally created for Unix systems and now specified by POSIX, with implementations maintained by operating system and toolchain vendors. It is used to combine object files and other resources into static libraries, and is commonly processed by archivers, linkers, and build tools. The format is simple and generally safe, though malformed archives may trigger errors in older utilities.
Magic Bytes
Offset 0
21 3C 61 72 63 68 3E 0A
Sources: Gary Kessler
Validation Code
How to validate .lib files in 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) == signatureHow to validate .lib files in 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
/api/v1/lib
curl https://filesignature.org/api/v1/lib
See the full API documentation for all endpoints and parameters.
Related Formats
Frequently Asked Questions
What is a .lib file?
A .lib file is an Unix archiver file. The Unix archiver (ar) format is a legacy archive file format originally created for Unix systems and now specified by POSIX, with implementations maintained by operating system and toolchain vendors. It is used to combine object files and other resources into static libraries, and is commonly processed by archivers, linkers, and build tools. The format is simple and generally safe, though malformed archives may trigger errors in older utilities.
What are the magic bytes for .lib files?
The magic bytes for Unix archiver (.lib) files are 21 3C 61 72 63 68 3E 0A at byte offset 0. These bytes identify the file format more reliably than the extension alone.
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.