system_setsid Interface

    system_setsid(3f) - [M_system:QUERY] create session and set the
                        process group ID of a session leader
    (LICENSE:PD)

    integer(kind=c_int) function system_setsid(pid)
    integer(kind=c_int) :: pid

    The setsid() function creates a new session, if the calling
    process is not a process group leader. Upon return the calling
    process shall be the session leader of this new session, shall be
    the process group leader of a new process group, and shall have no
    controlling terminal. The process group ID of the calling process
    shall be set equal to the process ID of the calling process. The
    calling process shall be the only process in the new process
    group and the only process in the new session.

    Upon successful completion, setsid() shall return the value
    of the new process group ID of the calling process. Otherwise,
    it shall return -1 and set errno to indicate the error.

    The setsid() function shall fail if:

     o The calling process is already a process group leader
     o the process group ID of a process other than the calling
       process matches the process ID of the calling process.

program demo_system_setsid
use M_system,      only : system_setsid
implicit none
   write(*,*)'SID=',system_setsid()
end program demo_system_setsid