I've had problems using /usr/bin/php on CPanel as it is compiled as a "cgi-fcgi" binary and not "cli". Try using /usr/local/bin/php or, as it is first in the path anyway, just use 'php' instead:
php /path/to/script.php
If you want to run the script as an executable, give it +x perms and use the following as the first line of the script:
I hope your problem is with path & php binary as well.
If you have fixed the path as per older answers, please use php-cli instead of php command while running cron job.
It may be possible php_sapi_name() is not returning cli. Its returning something else like cgi-fcgi etc.