Mac升级到yosemite后，php也自动升级，运行项目的时候发现后台验证码显示不出来。调试一下发现imagetfftext这个函数不存在，应该gd没有安装完全，因为Mac上的php实现系统自带的，只能通过重新安装php来解决【不能通过安装扩展来处理】，经过对比发现使用homebrew安装会方便点。。。

首先重新安装freetype,jpeg,libpng,gd

#先删除之前的再安装新的，没有安装过的则直接跳过即可

sudo brew rm freetype jpeg libpng gd zlib

brew install freetype jpeg libpng gd zlib

• 安装过程可能会报下面的错误：

  Error: You must "brew link libpng" before gd can be installed

  解决办法：

  #注意添加overwrite，否则可能会提示冲突
  
  sudo brew link --overwrite libpng
  

下来就是安装php了【这里安装会覆盖之前的php】

#这里我选择版本的是php5.6，因为之前系统默认的是php5.5，用高版本的覆盖放心点

sudo brew install homebrew/php/php56

• 安装完成之后有如下提示：

  To enable PHP in Apache add the following to httpd.conf and restart Apache:
  
      LoadModule php5_module    /usr/local/opt/php56/libexec/apache2/libphp5.so
  
  The php.ini file can be found in:
  
      /usr/local/etc/php/5.6/php.ini
  
  ✩✩✩✩ PEAR ✩✩✩✩
  
  If PEAR complains about permissions, 'fix' the default PEAR permissions and config:
  
      chmod -R ug+w /usr/local/Cellar/php56/5.6.10/lib/php
  
      pear config-set php_ini /usr/local/etc/php/5.6/php.ini system
  
  ✩✩✩✩ Extensions ✩✩✩✩
  
  If you are having issues with custom extension compiling, ensure that
  
  you are using the brew version, by placing /usr/local/bin before /usr/sbin in your PATH:
  
        PATH="/usr/local/bin:$PATH"
  
  PHP56 Extensions will always be compiled against this PHP. Please install them
  
  using --without-homebrew-php to enable compiling against system PHP.
  
  ✩✩✩✩ PHP CLI ✩✩✩✩
  
  If you wish to swap the PHP you use on the command line, you should add the following to ~/.bashrc,
  
  ~/.zshrc, ~/.profile or your shell's equivalent configuration file:
  
        export PATH="$(brew --prefix homebrew/php/php56)/bin:$PATH"
  
  ✩✩✩✩ FPM ✩✩✩✩
  
  To launch php-fpm on startup:
  
      mkdir -p ~/Library/LaunchAgents
  
      cp /usr/local/opt/php56/homebrew.mxcl.php56.plist ~/Library/LaunchAgents/
  
      launchctl load -w ~/Library/LaunchAgents/homebrew.mxcl.php56.plist
  
  The control script is located at /usr/local/opt/php56/sbin/php56-fpm
  
  OS X 10.8 and newer come with php-fpm pre-installed, to ensure you are using the brew version you need to make sure /usr/local/sbin is before /usr/sbin in your PATH:
  
    PATH="/usr/local/sbin:$PATH"
  
  You may also need to edit the plist to use the correct "UserName".
  
  Please note that the plist was called 'homebrew-php.josegonzalez.php56.plist' in old versions
  
  of this formula.
  
  To have launchd start homebrew/php/php56 at login:
  
      ln -sfv /usr/local/opt/php56/*.plist ~/Library/LaunchAgents
  
  Then to load homebrew/php/php56 now:
  
      launchctl load ~/Library/LaunchAgents/homebrew.mxcl.php56.plist
  

上面关键的是就是libphp5.so这个文件，其他的暂时可以忽略了。。。

最后就是修改apache的配置文件【httpd.conf】，把原来的libphp5.so文件路径替换为上面的，重启apache即可

sudo sudo vim /etc/apache2/httpd.conf

#这里别忘记要替换一下libphp.so的文件路径哦

sudo apachectl restart

自己测试 sudo brew install homebrew/php/php56 使用这种方式生成的 libphp5.so 文件的位置不在这段提示的位置"/usr/local/opt/php56/libexec/apache2/libphp5.so" 而是 “/usr/local/Cellar/php56/5.6.23/libexec/apache2/libphp5.so”（自己安装的是PHP56版本）

from segmentfault.com/a/1190000002924313