I'm running the PHP CLI through a NSTask in MacOS, but this question is more about the CLI itself. I'm listening to the stderr pipe, but nothing is output there no matter what file I try to run: If the file type is not a plain text, stdout sets to ? . If the file is a php script with errors, the error messages are still printed to stdout . Is there a switch to the interpreter to handle errors through stderr ? Do I have an option to detect errors other than parsing stdout ?

PHP CLI doesn't use stderr to output errors

I'm running the PHP CLI through a NSTask in MacOS, but this question is more about the CLI itself.

I'm listening to the stderr pipe, but nothing is output there no matter what file I try to run:

If the file type is not a plain text, stdout sets to ?.
If the file is a php script with errors, the error messages are still printed to stdout.

Is there a switch to the interpreter to handle errors through stderr? Do I have an option to detect errors other than parsing stdout?