Install and run PHP 7 on Raspbian (Raspberry Pi Debian)
Debian 8 (Jessie) is locked to PHP 5.6 and will not come with an upgrade to PHP 7. Soon after launch time there is the excellent Dotdeb.org available to users of Debian.
Dotdeb is a great resource and easy to install, but for Raspberry Pi you'll need to look elsewhere. The reason is the ARM CPU; In 2015 most servers still use the x86 and x86-64 architectures (Intel and AMD processors mostly) and ARM does not have the domination here as it does in the mobile space.
Installing from APT
For one option for prebuilt APT packages for Raspbian you can look at Mati75's private Debian repository, which seems quite up-to-date, and have plenty of packages such as bz2, cgi, cli, curl, dbg, dev, fpm, gd, imap, interbase, intl, json, ldap, mcrypt, mysql, odbc, opcache, pgsql, phpdbg, pspell, readline, recode, snmp, sqlite3, sybase, tidy, xmlrpc and others.
To install PHP 7 from Mati75's repository (for Debian Jessie):
1. Add the following lines to your sources file (/etc/apt/sources.list):
deb http://repozytorium.mati75.eu/raspbian jessie-backports main contrib non-free #deb-src http://repozytorium.mati75.eu/raspbian jessie-backports main contrib non-free
2. Add repository public key
gpg --keyserver pgpkeys.mit.edu --recv-key CCD91D6111A06851
gpg --armor --export CCD91D6111A06851 | apt-key add -
3. Run APT update
apt-get update
4. Install PHP 7
apt-get install php7.0 php7.0-opcache
In addition you'll likely need other extensions for db access and more, they are prefixed as php7.0-xx. For installing a web server like Nginx you can follow tutorials such as Bolting on PHP with PHP-FPM. Obviously php5 packages will be php7.0 packages instead, but otherwise Debian and Ubuntu tutorials work fine with Raspbian.
Installing from source
If no the repo does not work for you, then you can look into building PHP 7 from source yourself. For initial insight on how to build PHP 7 on Raspbian read about Installing PHP 7 on Debian 8 Jessie. These configure options seem to work fine:
'./configure' '--prefix=/opt/php7' '--enable-fpm' '--with-libxml-dir=/usr/lib/x86_64-linux-gnu/' '--enable-bcmath' '--enable-exif' '--enable-intl' '--enable-calendar' '--enable-zip' '--enable-soap' '--enable-ftp' '--enable-pcntl' '--enable-mbstring' '--with-openssl' '--with-curl' '--with-pdo-mysql=mysqlnd' '--with-mcrypt' '--with-zlib' '--with-bz2' '--with-config-file-path=/opt/php7/etc/' '--with-config-file-scan-dir=/opt/php7/etc/modules/'
Read more about PHP 7:
- Symfony Benchmarks: PHP 5.6, HHVM 3.11 and PHP 7.0.1
- Speeding up the web with PHP 7
- Performance insight into the upcoming release of PHP 7
- Migrating from PHP 5.6.x to PHP 7.0.x
- PHP Data Structures and the impact of PHP 7 on them
- PHP-FPM vs. PHP-PM (on PHP 7 and HHVM)