program demo_system_getgrgid
use M_system, only : system_getgrgid
use M_system, only : system_getgid
implicit none
character(len=:),allocatable :: name
name=system_getgrgid( system_getgid() )
write(*,'("group[",a,"] for ",i0)')name,system_getgid()
end program demo_system_getgrgid