file->openWriteOnly

file->openWriteOnly is a member in the file Object group; call it on the receiver shown before the arrow.

file->openWriteOnly is called with member syntax on a receiver value. file->openWriteOnly touches paths or filesystem data. Resolve paths deliberately and avoid mixing visitor-provided path fragments with trusted server paths without validation.

In web-serving modes, request-targeted application file access cannot escape the configured document_root. That boundary can come from the .ini file, the --docroot flag used by the LaiRu HTTP server or FPM process, or FastCGI values such as DOCUMENT_ROOT and SCRIPT_FILENAME supplied by nginx or Apache. See the web root directory, FastCGI options, and LaiRu FPM pages for the deployment side of that boundary.