It would generate the scalar comma operator there, not the list construction version of the comma. That means it was never a list to start with. This is different from the C interfaces, which return -1 on failure. Exceptions to this rule are wait , waitpid , and syscall . Other functions do not, except accidentally.
Some functions appear in more than one place.
Functions obsoleted in perl5 dbmclose , dbmopen Portability Perl was born in Unix and can therefore access all common Unix system calls. In non-Unix environments, the functionality of some Unix system calls may not be available, or details of the available functionality may differ slightly.