program demo_set_environment_variable use M_system, only : set_environment_variable use iso_c_binding implicit none integer :: ierr !x! write(*,'(a)')'no environment variables containing "GRU":' call execute_command_line('env|grep GRU') !x! call set_environment_variable('GRU','this is the value',ierr) write(*,'(a,i0)')'now "GRU" should be defined, status=',ierr call execute_command_line('env|grep GRU') !x! call set_environment_variable('GRU2','this is the second value',ierr) write(*,'(a,i0)')'now "GRU" and "GRU2" should be defined, status =',ierr !x! call execute_command_line('env|grep GRU') end program demo_set_environment_variable