trying to create a ftp user with permissions - php

Question

So I'm trying to create a ftp user and give him permissions to a specific directory, but the user is not being created. When I echo the commands the directory is created and the permissions are given to the user but when i try to log with the credentials created it's not working. Please take a look. What am I doing wrong ?
$randomNum = substr(str_shuffle("0123456789abcdefghijklmnopqrstvwxyz"), 0, 8);
$randomPass = substr(str_shuffle("0123456789abcdefghijklmnopqrstvwxyz"), 0, 6);
$src = $request->path;
$dest = "/home/$randomNum";
echo $ssh->exec("mkdir $dest\n");
echo $ssh->exec("useradd -m -d $dest $randomNum\n");
echo $ssh->exec("passwd $randomNum\n");
echo $ssh->read('New password:');
echo $ssh->write($randomPass."\n");
echo $ssh->exec("nice -n 19 cp -Rf $src $dest && chown -Rf $randomNum:$randomNum $dest && exit\n");
$ssh->disconnect();

Answer 1

Assuming that randomNum is the username, randomPass the password and dest the home directory,
Change this:
echo $ssh->exec("mkdir $dest\n");
echo $ssh->exec("useradd -m -d $dest $randomNum\n");
echo $ssh->exec("passwd $randomNum\n");
echo $ssh->read('New password:');
echo $ssh->write($randomPass."\n");
echo $ssh->exec("nice -n 19 cp -Rf $src $dest && chown -Rf $randomNum:$randomNum $dest && exit\n");
To this:
$ssh->exec("useradd -M " . $randomNum. " -d " . $dest);
$ssh->exec("echo \"" . $randomNum . ":" . $randomPass . "\" | sudo chpasswd");
$ssh->exec("chown -R " . $randomNum . ":" . $randomNum . " " . $dest);

Answer 2

From your code:
echo $ssh->exec("passwd $randomNum\n");
echo $ssh->read('New password:');
echo $ssh->write($randomPass."\n");
For that command, in particular, you'd need to enable PTY mode for the reads / writes to work. You can do so by doing $ssh->enablePTY() before the command. It might not be a bad idea to do $ssh->disablePTY() after the command, however.
Also, echo $ssh->write($randomPass."\n");... that's not really gonna have the desired effect. $ssh->write just returns true or false depending on the success or failure of the write command.