readline_callback_handler_install
Initializes the readline callback interface and terminal, prints the prompt and returns immediately
Description
true readline_callback_handler_install(string $prompt, callable $callback)
Sets up a readline callback interface then prints
prompt and immediately returns.
Calling this function twice without removing the previous
callback interface will automatically and conveniently overwrite the old
interface.
The callback feature is useful when combined with
stream_select as it allows interleaving of IO and
user input, unlike readline.
Parameters
-
prompt
-
The prompt message.
-
callback
-
The
callback function takes one parameter; the
user input returned.
Return Values
Always returns true.
Examples
Example #1 Readline Callback Interface Example
<?php
function rl_callback($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";
?>
See Also
- readline_callback_handler_remove
- readline_callback_read_char
- stream_select