php安装出现错误，高手解答一下，就差这一步了

Installing PEAR environment:      /usr/local/php//lib/php/
/lamp/php-5.2.6/sapi/cli/php: error while loading shared libraries: libltdl.so.3: cannot open shared object file: No such file or directory
make[1]: *** [install-pear-installer] Error 127
make: *** [install-pear] Error 2
[root@localhost php-5.2.6]#

无人解答？？？

yum install libtool
yum install libtool-ltdl

－－确认安装下libtool和libtool-ltdl这两个包