A (.a)
.a file signature | application/x-archive
The A file format is a Unix archive format associated with the ar utility, originally developed for Unix systems and maintained by standard toolchains that support archive creation and extraction. It is used primarily to group object files into static libraries and to package related build artifacts for software development and system distribution. It is generally safe to handle, though some variants are legacy formats and may be encountered mainly in older toolchains.
Magic Bytes
Offset 0
3D 3C 61 72 3E
Sources: Apache Tika
All Known Signatures
2 signature variants are documented for .a files across multiple sources.
| Hex Signature | Offset | Sources |
|---|---|---|
| 3D 3C 61 72 3E | 0 | Apache Tika |
| 21 3C 61 72 63 68 3E 0A | 0 | Apache Tika |
Extension
.a
MIME Type
application/x-archive
Byte Offset
0
Risk Level
Safe
Validation Code
How to validate .a files in Python
def is_a(file_path: str) -> bool:
"""Check if file is a valid A by magic bytes."""
signature = bytes([0x3D, 0x3C, 0x61, 0x72, 0x3E])
with open(file_path, "rb") as f:
return f.read(5) == signatureHow to validate .a files in Node.js
function isA(buffer: Buffer): boolean {
const signature = Buffer.from([0x3D, 0x3C, 0x61, 0x72, 0x3E]);
return buffer.subarray(0, 5).equals(signature);
}How to validate .a files in Go
func IsA(data []byte) bool {
signature := []byte{0x3D, 0x3C, 0x61, 0x72, 0x3E}
if len(data) < 5 {
return false
}
return bytes.Equal(data[:5], signature)
}API Endpoint
/api/v1/a
curl https://filesignature.org/api/v1/a
See the full API documentation for all endpoints and parameters.
Related Formats
Frequently Asked Questions
What is a .a file?
A .a file is identified by the magic bytes 3D 3C 61 72 3E at byte offset 0. The A file format is a Unix archive format associated with the ar utility, originally developed for Unix systems and maintained by standard toolchains that support archive creation and extraction. It is used primarily to group object files into static libraries and to package related build artifacts for software development and system distribution. It is generally safe to handle, though some variants are legacy formats and may be encountered mainly in older toolchains.
What are the magic bytes for .a files?
The magic bytes for A files are 3D 3C 61 72 3E at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.
How do I validate a .a file?
To validate a .a file, read the first bytes of the file and compare them against the known magic bytes (3D 3C 61 72 3E) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.
What is the MIME type for .a files?
The primary MIME type for .a files is application/x-archive.
Is it safe to open .a files?
A (.a) 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.