Debian stretch で php5 / php7.0 を切り替え

update-alternatives で OK かなと思ったのですが,

$ sudo update-alternatives --config php
There are 2 choices for the alternative php (providing /usr/bin/php).

  Selection    Path             Priority   Status

--------------------

* 0            /usr/bin/php7.0   70        auto mode
  1            /usr/bin/php5     50        manual mode
  2            /usr/bin/php7.0   70        manual mode
  Press <enter> to keep the current choice[*], or type selection number: 0
$ php -v
PHP 7.0.30-0+deb9u1 (cli) (built: Jun 14 2018 13:50:25) ( NTS )
Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.0.0, Copyright (c) 1998-2017 Zend Technologies
    with Zend OPcache v7.0.30-0+deb9u1, Copyright (c) 1999-2017, by Zend Technologies

apache では php5 のままです.

$ w3m -dump http://localhost/phpinfo.php|grep -m1 'PHP Version'
PHP Version 5.6.30-0+deb8u1

apache module を切り替えたらokでした.

$ sudo a2dismod php5
$ sudo a2enmod php7.0
$ systemctl restart apache2
環境
$ dpkg-query -W apache2 php5 libapache2-mod-php5 php7.0 libapache2-mod-php7.0
apache2 2.4.25-3+deb9u5
libapache2-mod-php5     5.6.30+dfsg-0+deb8u1
libapache2-mod-php7.0   7.0.30-0+deb9u1
php5    5.6.30+dfsg-0+deb8u1
php7.0  7.0.30-0+deb9u1
$ lsb_release -d
Description:    Debian GNU/Linux 9.5 (stretch)
$ uname -m
x86_64