tt_pattern_user(3)

NAME
     tt_pattern_user - return the value in a user data cell for a pattern
     object

SYNOPSIS
     #include <Tt/tt_c.h>
     void *tt_pattern_user(Tt_pattern p,
                           int key);

DESCRIPTION
     The tt_pattern_user() function returns the value in the indicated user
     data cell for the specified pattern object.

     Every pattern object allows an arbitrary number of user data cells that
     are each one word in size.  The user data cells are identified by integer
     keys.  The tool can use these keys in any manner to associate arbitrary
     data with a pattern object.

     The user data is part of the pattern object (that is, the storage buffer
     in the application); it is not part of the actual pattern.  The content
     of user cells has no effect on pattern matching.

     The p argument is a unique handle for a message pattern.  This handle is
     returned after tt_pattern_create() is called.  The key argument is the
     specified user data cell.  The application can use tt_pattern_user_set(3)
     to assign the keys to the user data cells that are part of the pattern
     object.  The value of each data cell must be unique for this pattern.

RETURN VALUE
     Upon successful completion, the tt_pattern_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 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_pattern_user_set(3), tt_pattern_create(3), tt_ptr_error(3).