PHP Cli: How to Read a Single Character of Input from the Tty (Without Waiting for the Enter Key)

PHP CLI: How to read a single character of input from the TTY (without waiting for the enter key)?

The solution for me was to set -icanon mode on the TTY (using stty). Eg.:

stty -icanon

So, the the code that now works is:

#!/usr/bin/php
<?php
system("stty -icanon");
echo "input# ";
while ($c = fread(STDIN, 1)) {
    echo "Read from STDIN: " . $c . "\ninput# ";
}
?>

Output:

input# fRead from STDIN: f
input# oRead from STDIN: o
input# oRead from STDIN: o
input# 
Read from STDIN: 

input# 

Props to the answer given here:

Is there a way to wait for and get a key press from a (remote) terminal session?

For more information, see:

http://www.faqs.org/docs/Linux-HOWTO/Serial-Programming-HOWTO.html#AEN92

Don't forget to restore the TTY when you're done with it...

Restoring the tty configuration

Resetting the terminal back to the way it was can be done by saving the tty state before you make changes to it. You can then restore to that state when you're done.

For example:

<?php

// Save existing tty configuration
$term = `stty -g`;

// Make lots of drastic changes to the tty
system("stty raw opost -ocrnl onlcr -onocr -onlret icrnl -inlcr -echo isig intr undef");

// Reset the tty back to the original configuration
system("stty '" . $term . "'");

?>

This is the only way to preserve the tty and put it back how the user had it before you began.

Note that if you're not worried about preserving the original state, you can reset it back to a default "sane" configuration simply by doing:

<?php

// Make lots of drastic changes to the tty
system("stty raw opost -ocrnl onlcr -onocr -onlret icrnl -inlcr -echo isig intr undef");

// Reset the tty back to sane defaults
system("stty sane");

?>

Is it possible to update screen and wait for user input at the same time with PHP?

Go for libevent http://www.php.net/manual/en/book.libevent.php

You can run your main loop while listening to console with a code roughly like this one:

<?php   
// you need libevent, installable via PEAR
$forever=true;
$base=event_base_new();
$console=event_buffer_new(STDIN,"process_console");
event_buffer_base_set($console,$base);
event_buffer_enable($console,EV_READ);
while ($forever) {
    event_base_loop($base,EVLOOP_NONBLOCK); // Non blocking poll to console listener
    //Do your video update process
}
event_base_free($base); //Cleanup
function process_console($buffer,$id) {
    global $base;
    global $forever;
    $message='';
    while ($read = event_buffer_read($buffer, 256)) {
        $message.=$read;
    }
    $message=trim($message);
    print("[$message]\n");
    if ($message=="quit") {
        event_base_loopexit($base);
        $forever=false;
    }
    else {
        //whatever.....
    }
}

Listen to stream from /dev/tty where return key is not necessary

Just a matter of using raw mode, at least with Node.js:

const {ReadStream} = require('stream');
const r = new ReadStream();
r.setRawMode(true);

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