tt_message_user(3)

NAME
     tt_message_user - retrieve the user information associated with a message
     object

SYNOPSIS
     #include <Tt/tt_c.h>
     void *tt_message_user(Tt_message m,
                           int key);

DESCRIPTION
     The tt_message_user() function retrieves the user information stored in
     data cells associated with the specified message object.

     The user data is part of the message object (that is, the storage buffer
     in the application); it is not a part of the actual message.  The
     application can, therefore, only retrieve user information that the
     application placed in the message.

     The m argument is the opaque handle for the message involved in this
     operation.  The key argument is the user data cell to be retrieved.  The
     user data cell must be unique for this message.

RETURN VALUE
     Upon successful completion, the tt_message_user() function returns the
     data cell, a piece of arbitrary user data that can hold a void *.  The
     application can use tt_ptr_error(3) to extract one of the following
     Tt_status values from the returned data:

        TT_OK   The operation completed successfully.

        TT_ERR_NOMP
                The ttsession(1) process is not running and the ToolTalk
                service cannot restart it.

        TT_ERR_POINTER
                The pointer passed does not point to an object of the correct
                type for this operation.

APPLICATION USAGE
     The application should use tt_free(3) to free any data stored in the
     address returned by the ToolTalk API.

     The user data cell is intended to hold an address.  If the address
     selected is equal to one of the Tt_status enumerated values, the result
     of the tt_ptr_error(3) function will not be reliable.

SEE ALSO
     Tttt_c(5), tt_ptr_error(3), tt_free(3).