Description:
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I'm running several web sites in a shared hosting that has dual version of PHP installed, PHP 4.3.10 (webhoster's) and 5.0.4 (compiled & installed manually). Everytime I update PHP I have to patch src/php_ini.c so it looks up PHP5RC instead of PHPRC, because PHPRC is already used by the PHP 4 installation for PHP 4 configuration file, and I want to use another configuration file for the PHP 5 installation.

Is it possible to add a new behavior to PHP 5 so it'll first look for PHP5RC, if it's not there then it'll use PHPRC, or any other configuration file paths accepted.

It will have minimal impact on any PHP installation because nobody should ever have used PHP5RC for any other purpose. And anyone with similar situations like I do can use the new environment variable to help in dual PHP installations (not everyone can afford the luxury of controlling their own webservers).

Reproduce code:
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Expected result:
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Actual result:
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