I have Solaris 2.7 with php-4.2.2 and have to install readline.
I had made libreadline.so in /usr/local/lib from readline-4.3 source code.
When I compile and make php --with-readline=/usr/local/lib its ok and get libphp4.so
When restarting apache, in error_log I get:
Invalid library (maybe not a PHP library) 'libreadline.so'
How to build a valid libreadline.so?