Mac安装php7.1并且替换php7.0

首先取消php70的链接：

brew unlink php70

接下来安装：

brew info php71

安装结果如下：

php@7.1: stable 7.1.25 (bottled) [keg-only]
General-purpose scripting language
https://secure.php.net/
/usr/local/Cellar/php@7.1/7.1.25 (513 files, 63.2MB)
  Poured from bottle on 2019-01-24 at 10:19:13
From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/php@7.1.rb
==> Dependencies
Build: httpd ✘, pkg-config ✔
Required: apr ✔, apr-util ✔, aspell ✔, autoconf ✔, curl-openssl ✔, freetds ✔, freetype ✔, gettext ✔, glib ✔, gmp ✔, icu4c ✔, jpeg ✔, libpng ✔, libpq ✔, libtool ✔, libzip ✔, mcrypt ✔, openldap ✔, openssl ✔, pcre ✔, sqlite ✔, tidy-html5 ✔, unixodbc ✔, webp ✔
==> Caveats
To enable PHP in Apache add the following to httpd.conf and restart Apache:
    LoadModule php7_module /usr/local/opt/php@7.1/lib/httpd/modules/libphp7.so

    <FilesMatch \.php$>
        SetHandler application/x-httpd-php
    </FilesMatch>

Finally, check DirectoryIndex includes index.php
    DirectoryIndex index.php index.html

The php.ini and php-fpm.ini file can be found in:
    /usr/local/etc/php/7.1/

php@7.1 is keg-only, which means it was not symlinked into /usr/local,
because this is an alternate version of another formula.

If you need to have php@7.1 first in your PATH run:
  echo 'export PATH="/usr/local/opt/php@7.1/bin:$PATH"' >> ~/.bash_profile
  echo 'export PATH="/usr/local/opt/php@7.1/sbin:$PATH"' >> ~/.bash_profile

For compilers to find php@7.1 you may need to set:
  export LDFLAGS="-L/usr/local/opt/php@7.1/lib"
  export CPPFLAGS="-I/usr/local/opt/php@7.1/include"

To have launchd start php@7.1 now and restart at login:
  brew services start php@7.1
Or, if you don't want/need a background service you can just run:
  php-fpm

如上可知如下信息，可以通过如下代码配置默认php:

echo 'export PATH="/usr/local/opt/php@7.1/bin:$PATH"' >> ~/.bash_profile
echo 'export PATH="/usr/local/opt/php@7.1/sbin:$PATH"' >> ~/.bash_profile

重启php7.1使用如下方法：

brew services start php@7.1

然后配置地址为：

/usr/local/etc/php/7.1/

其他版本升级:

# 升级为7.4
brew install php@7.4