readline_callback_handler_install

(PHP 5 >= 5.1.0, PHP 7, PHP 8)

readline_callback_handler_install — Initializes the readline callback interface and terminal, prints the prompt and returns immediately

Опис

function readline_callback_handler_install(string $prompt, callable $callback): true

Sets up a readline callback interface then prints prompt and immediately returns. Calling this function twice without removing the previous callback interface will automatically and conveniently overwrite the old interface.

The callback feature is useful when combined with stream_select() as it allows interleaving of IO and user input, unlike readline().

This function is only available if the readline library PHP was built against supports it. It is not available on Windows.

Параметри

prompt: The prompt message.
callback: The callback function takes one parameter; the user input returned.

Значення, що повертаються

Завжди повертає true.

Журнал змін

Версія	Опис
8.5.0	The return type is `true` now; previously, it was bool.

Приклади

Приклад #1 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";
?>

Прогляньте також

readline_callback_handler_remove() - Removes a previously installed callback handler and restores terminal settings
readline_callback_read_char() - Reads a character and informs the readline callback interface when a line is received
stream_select() - Runs the equivalent of the select() system call on the given arrays of streams with a timeout specified by seconds and microseconds

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User Contributed Notes 1 note

down

thflori ¶

8 years ago

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;
}

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