(PHP 4 >= 4.2.0, PHP 5)
posix_get_last_error -- Retrieve the error number set by the last posix function that failedRetrieve the error number set by the last posix function that failed. The system error message associated with the errno may be checked with posix_strerror().
Returns the errno (error number) set by the last posix function that failed. If no errors exist, 0 is returned.