PHP Manual: A Complete PHP/FFI/preloading Example

A Complete PHP/FFI/preloading Example

php.ini

ffi.enable=preload
opcache.preload=preload.php

preload.php

<?php
FFI::load(__DIR__ . "/dummy.h");
opcache_compile_file(__DIR__ . "/dummy.php");
?>

dummy.h

#define FFI_SCOPE "DUMMY"
#define FFI_LIB "libc.so.6"
 
int printf(const char *format, ...);

dummy.php

<?php
final class Dummy {
    private static $ffi = null;
    function __construct() {
        if (is_null(self::$ffi)) {
            self::$ffi = FFI::scope("DUMMY");
        }
    }
    function printf($format, ...$args) {
       return (int) self::$ffi->printf($format, ...$args);
    }
}
?>

test.php

<?php
$d = new Dummy();
$d->printf("Hello %s!\n", "world");
?>