portAlternativeTags.php

<?php

/*
 * Note: This script will directly modify the .php files in the given directory.
 * It is assumed that the code is under version control, so you can easily review
 * the changes using `git diff` or similar.
 */

function usageError() {
    die("Usage: php -d asp_tags=1 portAlternativeTags.php dir/\n");
}

if ($argc !== 2) {
    usageError();
}

$dir = $argv[1];
if (!is_dir($dir)) {
    echo "\"$dir\" is not a directory.\n";
    usageError();
}

if (!ini_get('asp_tags')) {
    echo "asp_tags must be enabled.\n";
    usageError();
}

$it = new RecursiveIteratorIterator(
    new RecursiveDirectoryIterator($dir),
    RecursiveIteratorIterator::LEAVES_ONLY
);

foreach ($it as $file) {
    if (!preg_match('/\.php$/', $file)) {
        continue;
    }

    $code = file_get_contents($file);

    $tokens = token_get_all($code);
    $tokens = portTags($tokens);

    $code = tokensToCode($tokens);

    file_put_contents($file, $code);
}

function portTags(array $tokens) {
    foreach ($tokens as $i => &$token) {
        if ($token[0] === T_OPEN_TAG) {
            if (strpos($token[1], '<?') === 0) {
                continue;
            }

            $token[1] = '<?php';
            if (!isset($tokens[$i]) || $tokens[$i][0] !== T_WHITESPACE) {
                $token[1] .= ' ';
            }
        } else if ($token[0] === T_OPEN_TAG_WITH_ECHO) {
            if ($token[1] === '<?=') {
                continue;
            }

            $token[1] = '<?=';
        } else if ($token[0] === T_CLOSE_TAG) {
            if (strpos($token[1], '?>') === 0) {
                continue;
            }

            if (preg_match('~^(?:%>|</script\s*>)(\s*)$~'i, $token[1], $matches)) {
                $token[1] = '?>' . $matches[1];
            }
        }
    }

    return $tokens;
}

function tokensToCode(array $tokens) {
    $code = '';
    foreach ($tokens as $token) {
        if (is_array($token)) {
            $code .= $token[1];
        } else {
            $code .= $token;
        }
    }
    return $code;
}