Compiling PHP 5.2.x / cannot find -lltdl

When compiling PHP from source, some of the CentOS users reported that they getting errors like below:

/usr/bin/ld: cannot find -lltdl
collect2: ld returned 1 exit status

What you need to do, is just follow the below steps.

Verify that the libtool and libtool-ltdl packages are installed.
Symlink libltdl.so to libltdl.so.x.x.x

If libtool and libtool-ltdl already exist, you may go [...]