daemon(3)                                                     daemon(3)

  daemon()

  NAME

    daemon() - run in the background

  SYNOPSIS

    #include 

    int daemon (int nochdir, int noclose)

  DESCRIPTION

    The daemon(3) call is an interface to allow a program to become a system
    daemon. The function causes the calling program to fork(2); the parent
    exits and the child then performs a setsid(2). This disassociates the
    process from its current process group, session, and controlling terminal.
    On successful completion of this call, the process is the session leader
    of a group in which it is the only member, and the session has no
    controlling terminal.

    If nochdir is zero, the process changes its current working directory to
    the installed root of INTERIX. Otherwise the current working directory is
    unchanged.

    If noclose is zero, the process redirects standard input, standard output,
    and standard error to /dev/null. Otherwise the standard file handles
    remain directed at the terminal that was previously the controlling
    terminal.

  RETURN VALUES

    The daemon(3) function returns 0 on success; on failure, it returns -1 and
    sets the global variable errno.

  ERRORS

    The daemon(3) function can fail for the following reasons:

    [EAGAIN]
        The system-imposed limit on the total number of processes under
        execution would be exceeded. This limit is configuration-dependent.

    [EAGAIN]
        The system-imposed limit on the total number of processes under
        execution by a single user would be exceeded.

    [EPERM]
        The calling process is already a process group leader, or the process
        group ID of a process other than the calling process matches the
        process ID of the calling process.

  SEE ALSO

    fork(2)

    setsid(2)

  USAGE NOTES

    The daemon function is thread safe.

    The daemon function is not async-signal safe.