0 Successful completion. x On error, the function sets the return value to one of the following: o EACCES - The user process does not have appropriate privileges enabled to access the user authorization file. o EIO - An I/O error has occurred. o EINTR - A signal was intercepted during getgrnam. o EMFILE - OPEN_MAX file descriptors are currently open in the calling process. o ENFILE - The maximum allowable number of files is currently open in the system. o ERANGE - Insufficient storage was supplied through the buffer and bufsize arguments to contain the data to be referenced by the resulting group structure.