NAME

       XAddHost,  XAddHosts,  XListHosts,  XRemoveHost,  XRemoveHosts,  XSetAccessControl, XEnableAccessControl,
       XDisableAccessControl, XHostAddress, XServerInterpretedAddress - control host  access  and  host  control
       structure

SYNTAX

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

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

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

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

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

       int XSetAccessControl(Display *display, int mode);

       int XEnableAccessControl(Display *display);

       int XDisableAccessControl(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 DisableAccess.

       nhosts_return
                 Returns the number of hosts currently in the access control list.

       num_hosts Specifies the number of hosts.

       state_return
                 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 disabled.  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 control 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
       machine 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, FamilyInternet6, FamilyServerInterpreted, FamilyDECnet, or  FamilyChaos.   The  length
       member  specifies  the  length  of  the  address in bytes.  The address member specifies a pointer to the
       address.

       For the ServerInterpreted family, the length is ignored  and  the  address  member  is  a  pointer  to  a
       XServerInterpretedAddress structure which contains:

       typedef struct {
               int typelength;         /* length of type string, in bytes */
               int valuelength;        /* length of value string, in bytes */
               char *type;             /* pointer to where to find the type string */
               char *value;            /* pointer to where to find the address */
       } XServerInterpretedAddress;

       The  type  and  value  members point to strings representing the type and value of the server interpreted
       entry.  These strings may not be NULL-terminated so  care  should  be  used  when  accessing  them.   The
       typelength and valuelength members specify the length in byte of the type and value strings.

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(3)
       Xlib - C Language X Interface