Listing 2-13 – Apple Network Setup User Manual

Page 44

C H A P T E R 2

Using Network Setup

Working with Sets

The

MyFindActiveSet

routine in Listing 2-13 implements the first two steps. It

starts by getting a list of all of the set entities by calling the

MyGetEntitiesList

routine (Listing 2-5). Then

MyFindActiveSet

iterates through all of the set

entities, reading the

kOTCfgSetsStructPref

preference of each set entity. That

preference maps to the

CfgSetsStruct

structure, which contains an

fFlags

member. One bit of the

fFlags

member,

kOTCfgSetsFlagActiveMask

, indicates

whether this set entity is the active set entity. If it is, the routine breaks out of
the loop and returns the set’s entity reference to the caller.

Listing 2-13

Finding the active set entity

static OSStatus MyFindActiveSet(CfgDatabaseRef dbRef,

CfgAreaID area,

CfgEntityRef *activeSet)

{

OSStatus err;

CfgEntityRef **entityRefs;

ItemCount entityCount;

ItemCount entityIndex;

Boolean found;

CfgSetsStruct thisStruct;

assert(dbRef != nil);

assert(area != kInvalidCfgAreaID);

entityRefs = (CfgEntityRef **) NewHandle(0);

err = MemError();

if (err == noErr) {

err = MyGetEntitiesList(dbRef, area,

kOTCfgClassSetOfSettings, kOTCfgTypeSetOfSettings,

entityRefs, nil);

}

if (err == noErr) {

HLock( (Handle) entityRefs );

assert(MemError() ==

noErr);

entityCount = GetHandleSize( (Handle) entityRefs ) / sizeof(CfgEntityRef);

found = false;

for (entityIndex = 0; entityIndex < entityCount; entityIndex++) {

err = MyReadFixedSizePref(dbRef, &(*entityRefs)[entityIndex],