安装phalcon 开发工具
先下载：https://github.com/phalcon/phalcon-devtools

下载后，解压缩。

.[root@localhost web]# cd phalcon-devtools-3.2.12
[root@localhost phalcon-devtools-3.2.12]# phalcon.sh

Phalcon Developer Tools Installer

Make sure phalcon.sh is in the same dir as phalcon.php
and that you are running this with sudo or as root.

Installing Devtools...
Working dir is: /web/phalcon-devtools-3.2.12
Generating symlink...

Done. Phalcon Developer Tools installed!
Thank you for using Phalcon Developer Tools!
We hope that Phalcon Developer Tools helps to make your life easier.

In case of problems: https://github.com/phalcon/phalcon-devtools/issues
and: https://forum.phalconphp.com

To start using Phalcon Developer Tools you need to run 'source /root/.bash_profile'
/web/phalcon-devtools-3.2.12/phalcon.sh: line 150: php: command not found

[root@localhost phalcon-devtools-3.2.12]# php -v
bash: php: command not found
当报上面的错时，是没有添加路径。
所以，php -v 会报错。

通过phpinfo()查看到：php目录在：/usr/local/php/etc/php.ini
cd /usr/local/php
里面的bin目录。
将 /usr/local/php/bin目录添加到PATH中
修改：
cd ~
我这里的 ~ 即是 /root目录。你要注意用自己的。
vim .bash_profile
添加一句。
export PATH=$PATH:/usr/local/php/bin
保存之后。
source /root/.bash_profile

[root@localhost ~]# source /root/.bash_profile
[root@localhost ~]# php -v
PHP 7.2.4 (cli) (built: Apr 24 2018 22:31:16) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies
with Zend OPcache v7.2.4, Copyright (c) 1999-2018, by Zend Technologies

现在再次回到，phalcon 开发工具的目录：就正常了！
[root@localhost phalcon-devtools-3.2.12]# phalcon.sh

Phalcon DevTools (3.2.12)

Available commands:
info (alias of: i)
commands (alias of: list, enumerate)
controller (alias of: create-controller)
module (alias of: create-module)
model (alias of: create-model)
all-models (alias of: create-all-models)
project (alias of: create-project)
scaffold (alias of: create-scaffold)
migration (alias of: create-migration)
webtools (alias of: create-webtools)
serve (alias of: server)
console (alias of: shell, psysh)