Fatal error: Call to undefined function imagettftext() in /var/www/apev.cn/htdocs/include/captcha.class.php on line 66
缺少 imagettftext() 函数造成生成验证码失败，解决办法是安装 freetype 并且重新编译 php，并且带上此参数。
make clean ./configure --with-gd \ --enable-gd-native-ttf \ --with-ttf \ --with-freetype-dir=/usr/lib/ \ --with-jpeg-dir=/usr/lib/libjpeg.so.62 \ --enable-exif \ make && make install