readline_callback_handler_install()

(PHP 5 >= 5.1.0, PHP 7)

初始化一个 readline 回调接口，然后终端输出提示信息并立即返回

说明

readline_callback_handler_install(string $prompt,callable $callback): bool

设置一个 readline 回调接口然后输出$prompt并立即返回.第二次调用这个函数不需要移除上一个回调接口，这个函数将自动覆盖旧的接口.

当配合stream_select()时回调的特性非常有用，它允许在 IO 与用户输入间交叉进行，不像readline().

参数

$prompt: 提示信息.
$callback: $callback函数需要一个参数;用户输入将被返回.

返回值

成功时返回TRUE，或者在失败时返回FALSE。

范例

Readline Callback Interface Example

<?php
function rl_callback($ret)
{
    global $c, $prompting;
    echo "You entered: $ret\n";
    $c++;
    if ($c > 10) {
        $prompting = false;
        readline_callback_handler_remove();
    } else {
        readline_callback_handler_install("[$c] Enter something: ", 'rl_callback');
    }
}
$c = 1;
$prompting = true;
readline_callback_handler_install("[$c] Enter something: ", 'rl_callback');
while ($prompting) {
    $w = NULL;
    $e = NULL;
    $n = stream_select($r = array(STDIN), $w, $e, null);
    if ($n && in_array(STDIN, $r)) {
        // read a character, will call the callback when a newline is entered
        readline_callback_read_char();
    }
}
echo "Prompting disabled. All done.\n";
?>

参见

readline_callback_handler_remove()移除上一个安装的回调函数句柄并且恢复终端设置
readline_callback_read_char()当一个行被接收时读取一个字符并且通知 readline 调用回调函数
stream_select()Runs the equivalent of the select()system call on the given arrays of streams with a timeout specified by tv_sec and tv_usec

To read byte wise and multi line you can check the line_buffer from readline_info:
<?php
function read(int $count, string $prompt = null): string
{
  $previous = '';
  readline_callback_handler_install($prompt ?? " \e[D", function ($str) use (&$previous) {
    $previous .= $str . PHP_EOL;
  });
  do {
    $r = array(STDIN);
    $n = stream_select($r, $w, $e, null);
    if ($n && in_array(STDIN, $r)) {
      readline_callback_read_char();
      $str = $previous . readline_info('line_buffer');
    }
  } while (mb_strlen($str) < $count); // use strlen if you need the exact byte count
  readline_callback_handler_remove();
  return $str;
}