macOS conversion from CFTypeRef to CFStringRef without full expression

[vishal.chauhan]

Dear All,

I want to convert from CFTypeRef to CFStringRef, I am using the following code -

CFStringRef myString = CFCopyDescription (value);

But is gives the string with expression but I want only its value.
If anybody knows how to do that then plz help me out.


Thanks.
Vishal

 

[gnasher729]

Dear All,

I want to convert from CFTypeRef to CFStringRef, I am using the following code -

CFStringRef myString = CFCopyDescription (value);

But is gives the string with expression but I want only its value.
If anybody knows how to do that then plz help me out.

I am confused what it actually is that you want to achieve.

"CFTypeRef" is not one specific kind of Core Foundation object, it is more something like "void *"; it says "this is some kind of Core Foundation object, but I don't know which one". So a CFTypeRef could really be a CFStringRef, or a CFNumberRef, or a CFDictionaryRef, or anything else.

So if that CFTypeRef is actually a CFDictionaryRef, just as an example, what would you want as the result?

Or, since getting a CFStringRef is not what you actually want to achieve but only some step on the way, what is it that you actually want to achieve?

 

[vishal.chauhan]

Hi,

Thanks for reply.
here is the detailed description what I want to achieve.

I am using the following code to get a volume name from IORegistery.

DASessionRef session = NULL;
	DADiskRef disk = NULL;
	CFDictionaryRef ddref = NULL;
	CFTypeRef val = nil;

session = DASessionCreate(kCFAllocatorDefault);

disk = DADiskCreateFromBSDName(kCFAllocatorDefault,session ,path); ///here path is in the form /dev/rdisk1

		ddref = DADiskCopyDescription(disk);
		if (! ddref) {
                   ///some message here
		}
				
CFDictionaryGetValueIfPresent(ddref,(kDADiskDescriptionVolumeNameKey),&val);
		
		
if(val)
{
	CFStringRef myString = CFCopyDescription (val);
	const char *VolumeName = CFStringGetCStringPtr(myString,          kCFStringEncodingMacRoman);

printf(" %s \n", VolumeName);
}

And I want to print volume name.
But it print a expresssion like <CFString 0x40e310 [0xa080a1c0]>{contents = "Macintosh HD"}

But what actually I want is that it should only print Macintosh HD.

Thanks.
Vishal

 

[tizz]

Hi,

Thanks for reply.
here is the detailed description what I want to achieve.

I am using the following code to get a volume name from IORegistery.

DASessionRef session = NULL;
    DADiskRef disk = NULL;
    CFDictionaryRef ddref = NULL;
    CFTypeRef val = nil;

session = DASessionCreate(kCFAllocatorDefault);

disk = DADiskCreateFromBSDName(kCFAllocatorDefault,session ,path); ///here path is in the form /dev/rdisk1

        ddref = DADiskCopyDescription(disk);
        if (! ddref) {
                   ///some message here
        }
               
CFDictionaryGetValueIfPresent(ddref,(kDADiskDescriptionVolumeNameKey),&val);
       
       
if(val)
{
    CFStringRef myString = CFCopyDescription (val);
    const char *VolumeName = CFStringGetCStringPtr(myString,          kCFStringEncodingMacRoman);

printf(" %s \n", VolumeName);
}

And I want to print volume name.
But it print a expresssion like <CFString 0x40e310 [0xa080a1c0]>{contents = "Macintosh HD"}

But what actually I want is that it should only print Macintosh HD.

Thanks.
Vishal

in order to print a CFStringRef you should use this
Boolean CFStringGetCString(CFStringRef theString, char *buffer, CFIndex bufferSize, CFStringEncoding encoding);