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