Determine if the volume is a disk image (DMG) from code
From Objective C (or Swift) I need to determine if the mounted volume is a disk image (installed from a .dmg file).
Similar questions led me to NSURL Volume Property Keys , but none seem to give the volume type / protocol.
However, I can see this information using a terminal function diskutil
in Protocol
:
~/Temp$ diskutil info /dev/disk8
Device Identifier: disk8
Device Node: /dev/disk8
Part of Whole: disk8
Device / Media Name: Apple UDIF read-only Media
Volume Name: Not applicable (no file system)
Mounted: Not applicable (no file system)
File System: None
Content (IOContent): GUID_partition_scheme
OS Can Be Installed: No
Media Type: Generic
Protocol: Disk Image <=== THIS IS WHAT I WANT
SMART Status: Not Supported
Total Size: 5.2 MB (5242880 Bytes) (exactly 10240 512-Byte-Units)
Volume Free Space: Not applicable (no file system)
Device Block Size: 512 Bytes
Read-Only Media: Yes
Read-Only Volume: Not applicable (no file system)
Ejectable: Yes
Whole: Yes
Internal: No
OS 9 Drivers: No
Low Level Format: Not supported
EDIT: Found some code that was at least used to do this, using this included extending a category in NSWorkspace . However, this is pre-ARC and I'm not sure if it will work.
Found it through this partial answer on another question ..
You can get this information using the DiskArbitration structure . To use the example below, you have to link it and #import
.
#import <DiskArbitration/DiskArbitration.h>
...
- (BOOL)isDMGVolumeAtURL:(NSURL *)url
{
BOOL isDMG = NO;
if (url.isFileURL) {
DASessionRef session = DASessionCreate(kCFAllocatorDefault);
if (session != nil) {
DADiskRef disk = DADiskCreateFromVolumePath(kCFAllocatorDefault, session, (__bridge CFURLRef)url);
if (disk != nil) {
NSDictionary * desc = CFBridgingRelease(DADiskCopyDescription(disk));
NSString * model = desc[(NSString *)kDADiskDescriptionDeviceModelKey];
isDMG = ([model isEqualToString:@"Disk Image"]);
CFRelease(disk);
}
CFRelease(session);
}
}
return isDMG;
}
Using:
BOOL isDMG = [someObject isDMGVolumeAtURL:[NSURL fileURLWithPath:@"/Volumes/Some Volume"]];
Hope this helps.