YAML YAML Ain’t Markup Language

SIGNATURE = bytes.fromhex("7469746c653a")
OFFSET = 0

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

const SIGNATURE = [0x74, 0x69, 0x74, 0x6c, 0x65, 0x3a];
const OFFSET = 0;

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

package fileid

import "bytes"

var isyamlSignature = []byte{0x74, 0x69, 0x74, 0x6c, 0x65, 0x3a}

const isyamlOffset = 0

func IsYaml(b []byte) bool {
	end := isyamlOffset + len(isyamlSignature)
	if len(b) < end {
		return false
	}
	return bytes.Equal(b[isyamlOffset:end], isyamlSignature)
}

const SIGNATURE: &[u8] = &[0x74, 0x69, 0x74, 0x6c, 0x65, 0x3a];
const OFFSET: usize = 0;

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

<?php
$signature = "\x74\x69\x74\x6c\x65\x3a";
$offset = 0;

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