The runkit_lint() function performs a syntax (lint) check on the specified php code testing for scripting errors. This is similar to using php -l from the commandline except runkit_lint() accepts actual code rather than a filename.
Note: Sandbox support (required for runkit_lint(), runkit_lint_file(), and the Runkit_Sandbox class) is only available with PHP 5.1 or specially patched versions of PHP 5.0 and requires that thread safety be enabled. See the README file included in the runkit package for more information.