Apple manual Using Network Setup, Reading and Writing Preferences

C H A P T E R 2

Using Network Setup

by calling OTCfgGetPrefsSize before you read the preference, as shown in Listing 2-10.

Listing 2-10Calling OTCfgGetPrefsSize to read a variable-size preference

static OSStatus MyReadVariableSizePref(CfgDatabaseRef dbRef, const CfgEntityRef *entity, OSType prefType,

Handle buffer)

{

OSStatus err;

OSStatus err2;

CfgEntityAccessID accessID;

ByteCount prefSize;

SInt8 s;

assert(dbRef != nil); assert(entity != nil); assert(buffer != nil);

err = OTCfgOpenPrefs(dbRef, entity, false, &accessID);

if (err	== noErr) {
err	= OTCfgGetPrefsSize(accessID, prefType, &prefSize);
if (err == noErr) {
	SetHandleSize(buffer, prefSize);
	err = MemError();
}
if (err == noErr) {
	s = HGetState(buffer);	assert(MemError()
== noErr);
	HLock(buffer);	assert(MemError()
== noErr);
	err = OTCfgGetPrefs(accessID, prefType, *buffer, prefSize);
	HSetState(buffer, s);	assert(MemError()

==noErr);

}

err2 = OTCfgClosePrefs(accessID); if (err == noErr) {

err = err2;

}

38Reading and Writing Preferences