XAddHost(XS)      X Version 11 (Release 5) 6 January 1993       XAddHost(XS)


 Name

    XAddHost - control host access and host control structure

 Syntax


    XAddHost(display, host)
          Display *display;
          XHostAddress *host;

    XAddHosts(display, hosts, num_hosts)
          Display *display;
          XHostAddress *hosts;
          int num_hosts;

    XHostAddress *XListHosts(display, nhosts_return, state_return)
          Display *display;
          int *nhosts_return;
          Bool *state_return;

    XRemoveHost(display, host)
          Display *display;
          XHostAddress *host;

    XRemoveHosts(display, hosts, num_hosts)
          Display *display;
          XHostAddress *hosts;
          int num_hosts;

    XSetAccessControl(display, mode)
          Display *display;
          int mode;

    XEnableAccessControl(display)
          Display *display;

    XDisableAccessControl(display)
          Display *display;


 Arguments


    display        Specifies the connection to the X server.

    host           Specifies the host that is to be added or removed.

    hosts          Specifies each host that is to be added or removed.

    mode           Specifies the mode.  You can pass EnableAccess or Disa-
                   bleAccess.

    nhostsreturn  Returns the number of hosts currently in the access con-
                   trol list.

    numhosts      Specifies the number of hosts.

    statereturn   Returns the state of the access control.

 Description

    The XAddHost function adds the specified host to the access control list
    for that display.  The server must be on the same host as the client
    issuing the command, or a ``BadAccess'' error results.

    XAddHost can generate ``BadAccess'' and ``BadValue'' errors.

    The XAddHosts function adds each specified host to the access control
    list for that display.  The server must be on the same host as the client
    issuing the command, or a ``BadAccess'' error results.

    XAddHosts can generate ``BadAccess'' and ``BadValue'' errors.

    The XListHosts function returns the current access control list as well
    as whether the use of the list at connection setup was enabled or dis-
    abled.  XListHosts allows a program to find out what machines can make
    connections.  It also returns a pointer to a list of host structures that
    were allocated by the function.  When no longer needed, this memory
    should be freed by calling XFree.

    The XRemoveHost function removes the specified host from the access con-
    trol list for that display.  The server must be on the same host as the
    client process, or a ``BadAccess'' error results.  If you remove your ma-
    chine from the access list, you can no longer connect to that server, and
    this operation cannot be reversed unless you reset the server.

    XRemoveHost can generate ``BadAccess'' and ``BadValue'' errors.

    The XRemoveHosts function removes each specified host from the access
    control list for that display.  The X server must be on the same host as
    the client process, or a ``BadAccess'' error results.  If you remove your
    machine from the access list, you can no longer connect to that server,
    and this operation cannot be reversed unless you reset the server.

    XRemoveHosts can generate ``BadAccess'' and ``BadValue'' errors.

    The XSetAccessControl function either enables or disables the use of the
    access control list at each connection setup.

    XSetAccessControl can generate ``BadAccess'' and ``BadValue'' errors.

    The XEnableAccessControl function enables the use of the access control
    list at each connection setup.

    XEnableAccessControl can generate a ``BadAccess'' error.

    The XDisableAccessControl function disables the use of the access control
    list at each connection setup.

    XDisableAccessControl can generate a ``BadAccess'' error.

 Structures

    The XHostAddress structure contains:

       typedef struct {
            int family;       /* for example FamilyInternet */
            int length;       /* length of address, in bytes */
            char *address;    /* pointer to where to find the address */
       } XHostAddress;

    The family member specifies which protocol address family to use (for
    example, TCP/IP or DECnet) and can be FamilyInternet, FamilyDECnet, or
    FamilyChaos.  The length member specifies the length of the address in
    bytes.  The address member specifies a pointer to the address.

 Diagnostics


    ``BadAccess''  A client attempted to modify the access control list from
                   other than the local (or otherwise authorized) host.

    ``BadValue''   Some numeric value falls outside the range of values
                   accepted by the request.  Unless a specific range is
                   specified for an argument, the full range defined by the
                   argument's type is accepted.  Any argument defined as a
                   set of alternatives can generate this error.

 See also

    XFree(XS)
    Xlib - C Language X Interface