Does drush need to be installed as root? Per http://docs.drush.org/en/master/install/

# Download latest stable release using the code below or browse to github.com/drush-ops/drush/releases.
php -r "readfile('http://files.drush.org/drush.phar');" &gt; drush
# Or use our upcoming release: php -r "readfile('http://files.drush.org/drush-unstable.phar');" &gt; drush

# Test your install.
php drush core-status

# Make `drush` executable as a command from anywhere. Destination can be anywhere on $PATH.
chmod +x drush
sudo mv drush /usr/local/bin

# Optional. Enrich the bash startup file with completion and aliases.
drush init


So I try it but get the following error:

[Michael@devserver ~]$ php -r "readfile('http://files.drush.org/drush.phar');" &gt; drush
[Michael@devserver ~]$ php drush core-status
PHP Warning:  pcntl_exec(): Error has occurred: (errno 13) Permission denied in phar:///home/Michael/drush/includes/startup.inc on line 359

Warning: pcntl_exec(): Error has occurred: (errno 13) Permission denied in phar:///home/Michael/drush/includes/startup.inc on line 359
Error has occurred executing the Drush script found at /home/Michael/drush
(errno 13) Permission denied
[Michael@devserver ~]


So then I try running it as root.

[Michael@devserver ~]$ su -
Password:
[root@devserver ~]# php /home/Michael/drush core-status
 PHP configuration      :  /etc/php.ini
 PHP OS                 :  Linux
 Drush script           :  /home/Michael/drush
 Drush version          :  8.1.2
 Drush temp directory   :  /tmp
 Drush configuration    :
 Drush alias files      :

[root@devserver ~]#


So, all is good, and I just need to install it as root?  Any way I can install it as a normal user?  Thanks
NOTE The issue described in the Question has now be fixed in the latest Drush version.

No, Drush does not need to be installed as root.

I've submitted Drush pull #2246 to update the current Drush install instructions. 

This install method fixes the issue as per Drush pull #2246:

# Download latest stable release using the code below or browse to github.com/drush-ops/drush/releases.
php -r "readfile('http://files.drush.org/drush.phar');" &gt; /tmp/drush
# Or use our upcoming release: php -r "readfile('http://files.drush.org/drush-unstable.phar');" &gt; /tmp/drush

# Test your install.
php /tmp/drush core-status

# Make `drush` executable as a command from anywhere. Destination can be anywhere on $PATH.
chmod +x /tmp/drush
sudo mv /tmp/drush /usr/local/bin

# Optional. Enrich the bash startup file with completion and aliases.
drush init