How to detect total available/free disk space on the iPhone/iPad device on iOS 11 - ios

Question

In iOS 11, I am not able to get the correct free size of the device(disk space) from the Dictionary key NSFileSystemFreeSize. Instead giving 34.4 GB it gives 4 GB free space.
Below is the code I am using
pragma mark - Formatter
- (NSString *)memoryFormatter:(long long)diskSpace
{
NSString *formatted;
double bytes = 1.0 * diskSpace;
double megabytes = bytes / MB;
double gigabytes = bytes / GB;
if (gigabytes >= 1.0)
formatted = [NSString stringWithFormat:#"%.2f GB", gigabytes];
else if (megabytes >= 1.0)
formatted = [NSString stringWithFormat:#"%.2f MB", megabytes];
else
formatted = [NSString stringWithFormat:#"%.2f bytes", bytes];
return formatted;
}
#pragma mark - Methods
- (NSString *)totalDiskSpace {
long long space = [[[[NSFileManager defaultManager] attributesOfFileSystemForPath:NSHomeDirectory() error:nil] objectForKey:NSFileSystemSize] longLongValue];
return [self memoryFormatter:space];
}
- (NSString *)freeDiskSpace {
long long freeSpace = [[[[NSFileManager defaultManager] attributesOfFileSystemForPath:NSHomeDirectory() error:nil] objectForKey:NSFileSystemFreeSize] longLongValue];
return [self memoryFormatter:freeSpace];
}
- (NSString *)usedDiskSpace {
return [self memoryFormatter:[self usedDiskSpaceInBytes]];
}
- (CGFloat)totalDiskSpaceInBytes {
long long space = [[[[NSFileManager defaultManager] attributesOfFileSystemForPath:NSHomeDirectory() error:nil] objectForKey:NSFileSystemSize] longLongValue];
return space;
}
- (CGFloat)freeDiskSpaceInBytes {
long long freeSpace = [[[[NSFileManager defaultManager] attributesOfFileSystemForPath:NSHomeDirectory() error:nil] objectForKey:NSFileSystemFreeSize] longLongValue];
return freeSpace;
}
- (CGFloat)usedDiskSpaceInBytes {
long long usedSpace = [self totalDiskSpaceInBytes] - [self freeDiskSpaceInBytes];
return usedSpace;
}

Answer 1

OBJECTIVE C (converted)
- (uint64_t)freeDiskspace
{
uint64_t totalSpace = 0;
uint64_t totalFreeSpace = 0;
__autoreleasing NSError *error = nil;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSDictionary *dictionary = [[NSFileManager defaultManager] attributesOfFileSystemForPath:[paths lastObject] error: &error];
if (dictionary)
{
NSNumber *fileSystemSizeInBytes = [dictionary objectForKey: NSFileSystemSize];
NSNumber *freeFileSystemSizeInBytes = [dictionary objectForKey:NSFileSystemFreeSize];
totalSpace = [fileSystemSizeInBytes unsignedLongLongValue];
totalFreeSpace = [freeFileSystemSizeInBytes unsignedLongLongValue];
NSLog(#"Memory Capacity of %llu MiB with %llu MiB Free memory available.", ((totalSpace/1024ll)/1024ll), ((totalFreeSpace/1024ll)/1024ll));
}
else
{
NSLog(#"Error Obtaining System Memory Info: Domain = %#, Code = %d", [error domain], [error code]);
}
return totalFreeSpace;
}

Answer 2

So if people have the problem of not getting the correct free size, use NSURL resourceValuesForKeys to get the free space.
[ fileURL resourceValuesForKeys:#[NSURLVolumeAvailableCapacityForImportantUsageKey ] error:&error];
double = availableSizeInBytes = [ results[NSURLVolumeAvailableCapacityForImportantUsageKey] doubleValue ];
Reference Why is `volumeAvailableCapacityForImportantUsage` zero?

Answer 3

Here's how I usually do it
func deviceRemainingFreeSpaceInBytes() -> Int64?
{
let documentDirectory = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).last!
guard
let systemAttributes = try? FileManager.default.attributesOfFileSystem(forPath: documentDirectory),
let freeSize = systemAttributes[.systemFreeSize] as? NSNumber
else {
// handle failure
return nil
}
return freeSize.int64Value // this returns bytes - scales as required for MB / GB
}

Answer 4

SWIFT 4:
func getFreeDiskspace() -> UInt64
{
let totalSpace: UInt64 = 0
let totalFreeSpace: UInt64 = 0
var error: Error? = nil
let paths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
let dictionary = try? FileManager.default.attributesOfFileSystem(forPath: paths.last ?? "")
if dictionary
{
var fileSystemSizeInBytes = dictionary[.systemSize]
var freeFileSystemSizeInBytes = dictionary[.systemFreeSize]
totalSpace = fileSystemSizeInBytes as UInt64? ?? 0
totalFreeSpace = freeFileSystemSizeInBytes as UInt64? ?? 0
print("Memory Capacity of \((totalSpace / 1024) / 1024) MiB with \((totalFreeSpace / 1024) / 1024) MiB Free memory available.")
}
else
{
print("Error Obtaining System Memory Info: Domain = \((error as NSError?)?.domain), Code = \(Int(error.code))")
return totalFreeSpace
}
}