FreeArc compressed file
application/x-internet-archive
Magic Bytes
Offset: 0
66 69 6C 65 64 65 73 63 3A 2F 2F
The FreeArc compressed file format is an open-source archival standard developed and maintained by Bulat Ziganshin. This format is primarily utilized for high-ratio data compression within software distribution packages, multimedia archives, and large-scale system backups. Although it employs dynamic algorithmic selection for storage efficiency, the specification is now considered a legacy standard, necessitating specific third-party extraction utilities because native support in modern universal file archivers is increasingly limited.
Validation Code
How to validate .arc files in Python
Python
def is_arc(file_path: str) -> bool:
"""Check if file is a valid ARC by magic bytes."""
signature = bytes([0x66, 0x69, 0x6C, 0x65, 0x64, 0x65, 0x73, 0x63, 0x3A, 0x2F, 0x2F])
with open(file_path, "rb") as f:
return f.read(11) == signatureHow to validate .arc files in Node.js
Node.js
function isARC(buffer: Buffer): boolean {
const signature = Buffer.from([0x66, 0x69, 0x6C, 0x65, 0x64, 0x65, 0x73, 0x63, 0x3A, 0x2F, 0x2F]);
return buffer.subarray(0, 11).equals(signature);
}
Go
func IsARC(data []byte) bool {
signature := []byte{0x66, 0x69, 0x6C, 0x65, 0x64, 0x65, 0x73, 0x63, 0x3A, 0x2F, 0x2F}
if len(data) < 11 {
return false
}
return bytes.Equal(data[:11], signature)
}API Endpoint
GET
/api/v1/arc
curl https://filesignature.org/api/v1/arc