To get PHP-PM working you need beside the php binary also php-cgi, which comes often with php. If not available try to install it:

Debian/Ubuntu (https://www.digitalocean.com/community/tutorials/how-to-upgrade-to-php-7-on-ubuntu-14-04)

apt-get install php7.0-cgi

By default cgi bin is in /usr/lib/cgi-bin/php, so you need to run:

sudo ln -s /usr/lib/cgi-bin/php /usr/bin/php7.0-cgi

Red Hat/Centos (RHEL-7, 6) (https://webtatic.com/packages/php70/)

install Webtatic first

yum install php70w-cli

Mac OS X - Homebrew (https://github.com/Homebrew/homebrew-php)

brew install php70

Mac OS X - Macports

port install php70-cgi

By default, PPM looks for a binary named php-cgi. If your PHP installation uses a different binary name, you can specify the full path to that binary with the php-cgi configuration option (for example: ppm config --cgi-path=/opt/local/bin/php-cgi70).

On Ubuntu for example per default pcntl_* functions are disabled. If you get Warning: pcntl_signal() has been disabled for security reasons, you should activate these functions:

Open /etc/php5/cgi/php.ini, find line disable_functions = pcntl_alarm,pcntl_fork, ... and place a ; in front of it:

; This directive allows you to disable certain functions for security reasons.
; It receives a comma-delimited list of function names.
; http://php.net/disable-functions
;disable_functions = pcntl_alarm,pcntl_fork, ...

$ git clone https://github.com/php-pm/php-pm.git
$ cd php-pm
$ composer install
$ ln -s `pwd`/bin/ppm /usr/local/bin/ppm
$ ppm --help