[root@jishu memcache-2.2.5]# /usr/local/php-5.2.11/bin/phpize
Configuring for:
PHP Api Version:         20041225
Zend Module Api No:      20060613
Zend Extension Api No:   220060519
Cannot find autoconf. Please check your autoconf installation and the $PHP_AUTOCONF environment variable is set correctly and then rerun this script.

1.
[root@jishu memcache-2.2.5]# cd /usr/src
[root@jishu memcache-2.2.5]# wget http://ftp.gnu.org/gnu/m4/m4-1.4.9.tar.gz
[root@jishu memcache-2.2.5]# tar -zvxf m4-1.4.9.tar.gz
[root@jishu memcache-2.2.5]# cd m4-1.4.9/
[root@jishu memcache-2.2.5]# ./configure && make && make install
[root@jishu memcache-2.2.5]# cd ../
[root@jishu memcache-2.2.5]# wget http://ftp.gnu.org/gnu/autoconf/autoconf-2.62.tar.gz
[root@jishu memcache-2.2.5]# tar -zvxf autoconf-2.62.tar.gz
[root@jishu memcache-2.2.5]# cd autoconf-2.62/
[root@jishu memcache-2.2.5]# ./configure && make && make install

2.
centos下执行 yum install autoconf 即可
ubuntu下执行 apt-get install autoconf 即可