TSV Tab-Separated Values

SIGNATURE = bytes.fromhex("696e64657809")
OFFSET = 0

def is_tsv(path: str) -> bool:
    with open(path, "rb") as f:
        f.seek(OFFSET)
        head = f.read(len(SIGNATURE))
    return head == SIGNATURE

const SIGNATURE = [0x69, 0x6e, 0x64, 0x65, 0x78, 0x09];
const OFFSET = 0;

// bytes: a Uint8Array / Buffer holding the start of the file
export function isTsv(bytes) {
  return SIGNATURE.every((byte, i) => bytes[OFFSET + i] === byte);
}

package fileid

import "bytes"

var istsvSignature = []byte{0x69, 0x6e, 0x64, 0x65, 0x78, 0x09}

const istsvOffset = 0

func IsTsv(b []byte) bool {
	end := istsvOffset + len(istsvSignature)
	if len(b) < end {
		return false
	}
	return bytes.Equal(b[istsvOffset:end], istsvSignature)
}

const SIGNATURE: &[u8] = &[0x69, 0x6e, 0x64, 0x65, 0x78, 0x09];
const OFFSET: usize = 0;

fn is_tsv(bytes: &[u8]) -> bool {
    bytes.get(OFFSET..OFFSET + SIGNATURE.len()) == Some(SIGNATURE)
}

<?php
$signature = "\x69\x6e\x64\x65\x78\x09";
$offset = 0;

function is_tsv(string $bytes): bool {
    global $signature, $offset;
    return substr($bytes, $offset, strlen($signature)) === $signature;
}