- array_map: documentation ( source)
- print_r: documentation ( source)
- explode: documentation ( source)
<?php
$str = "AWS-HMAC-SHA256 Credential=eyJhbGciOiJIUzI1NiIsIngtc3MiOjEy/20160911/cn/user-service/request,SignedHeaders=host;x-aws-date, Signature=d9ee2d43f2067e4b8857f15fa8fff27820051d95a4ec31e93be866f201e0797a";
$res = array_map(function($x){
return explode('=', $x)[1];
}, explode(',', $str));
print_r($res);