sudo apt-get install php7.0-dev

sudo apt-get install libevent-dev

sudo apt-get install pkg-config

sudo pecl install igbinary

cd ~

mkdir tmp

cd tmp/

wget https://launchpad.net/libmemcached/1.0/1.0.18/+download/libmemcached-1.0.18.tar.gz

tar xzvf libmemcached-1.0.18.tar.gz

cd libmemcached-1.0.18

libmemcached-1.0.18$ ./configure

./configure

make

sudo make install

https://github.com/php-memcached-dev/php-memcached/tree/php7

unzip php-memcached-php7.zip

cd php-memcached-php7/

phpize7.0 

./configure --enable-memcached-igbinary --disable-memcached-sasl

make

sudo make install

php -i | grep mem

cp json.ini igbinary.ini 

vi igbinary.ini :

    extension=igbinary.so

cp json.ini memcached.ini :

    extension=memcached.so

cd ../cli/conf.d/

sudo ln -s ../../mods-available/igbinary.ini  20-igbinary.ini

sudo ln -s ../../mods-available/memcached.ini  20-memcached.ini

cd ../../apache2/conf.d/

sudo ln -s ../../mods-available/igbinary.ini  20-igbinary.ini

sudo ln -s ../../mods-available/memcached.ini  20-memcached.ini

sudo service apache2 restart 

----- 如果上面安装 memcached 出现错误，导致安装不成功，请使用下面的命令代替 -------- 

sudo apt-get install -y php7.0-dev git pkg-config build-essential libmemcached-dev

[ sudo apt-get -f install ]  -- 上一句命令提示有误时执行这句 -- 

cd ~

git clone https://github.com/php-memcached-dev/php-memcached.git

cd php-memcached

git checkout php7

phpize

./configure --disable-memcached-sasl

make

sudo make install