`Could not open input file:` should be sent to stderr

[mvorisek]

Description

Repro command: php non-existent.php

Currently the output (Could not open input file: non-existent.php) is sent to stdout but it should be sent to stderr instead.

I have discovered when using php for interprocess communication where the stdout might be consumed as regular data causing protocol failure hard to understand, as in my case, only the first 4 bytes were consumed (and from Coul it was hard to identify the problem). Simply said, stdout should never contain any other data then data printed by a valid script.

[NattyNarwhal]

Looks like php_printf is used a bit in main/ and SAPIs for this - and if we're counting sundry diagnostic information, even more in extensions and Zend/. It probably shouldn't.

[iluuu1994]

Switching to STDERR should be fine. U fortunately, the error messages seem to be quite inconsistent with where they are printed.