Interactive shell using PHP

Question

Just wondering, is it possible to create an interactive shell, using PHP alone. I mean something like you have with databases, python, etc.

If it is, how?

Answer 1

Here's an expanded take on this. I've added an isCLI() check in case you're run your script both in CLI and on a web server. Otherwise the server could loop using my function. This solution will prompt the user, check the input, and re-prompt the user for fixed input if necessary. I rtrim() the input because if the user uses return to submit their entry, that may be appended to the entry. Validation is not necessary, just don't pass a function in that case.

function isCLI() {
    return (php_sapi_name() === 'cli' OR defined('STDIN'));
}

function userPrompt($message, $validator=null) {
    if (!isCLI()) return null;

    print($message);
    $handle = fopen ('php://stdin','r');
    $line = rtrim(fgets($handle), "\r\n");

    if (is_callable($validator) && !call_user_func($validator, $line)) {
        print("Invalid Entry.\r\n");
        return userPrompt($message, $validator);
    } else {
        print("Continuing...\r\n");
        return $line;
    }
}

// Example =====================

function validateSetLangCode($str) {
    return preg_match("/^[A-Z0-9]{3}-[A-Z]{2}$/", $str);
}

$code = userPrompt("Please enter the set / language codes. Use the format 'SET-EN', where SET is the three-letter set code and EN is the two-letter lang code. \r\n", 'validateSetLangCode') ?: 'SET-EN';
var_dump($code);