tt_pattern_user(library call) tt_pattern_user(library call)
NAMEtt_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 inte‐
ger keys. The tool can use these keys in any manner to associate arbi‐
trary data with a pattern object.
The user data is part of the pattern object (that is, the storage buf‐
fer 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_pat‐
tern_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 ser‐
vice 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
Tt/tt_c.h - Tttt_c(5), tt_pattern_user_set(3), tt_pattern_create(3),
tt_ptr_error(3).
tt_pattern_user(library call)
