Unable to delete the contents of a Directory in my Home Directory using NSDirectoryEnumerator - objective-c

Question

I have been unable to delete the contents of a directory using NSDirectoryEnumerator.
Here is my method:
- (BOOL) deleteDirectoryContents:(NSString *)directoryPath
{
BOOL success = FALSE;
BOOL isDir;
NSFileManager *fileManager = [NSFileManager defaultManager];
if ([fileManager fileExistsAtPath:directoryPath isDirectory:&isDir] && isDir)
{
NSDirectoryEnumerator *dirEnum = [fileManager enumeratorAtPath:directoryPath];
NSLog(#"dirEnum in deleteDirectoryContents is %#", dirEnum);
NSString *documentsName;
// NSLog(#"[dirEnum nextObject] is: %#", [dirEnum nextObject]);
while (documentsName = [dirEnum nextObject])
{
NSString *filePath = [directoryPath stringByAppendingString:documentsName];
NSLog(#"filePath is: %#", filePath);
BOOL isFileDeleted = [fileManager removeItemAtPath:filePath error:nil];
if(isFileDeleted == NO)
{
NSLog(#"All Contents not removed");
success = FALSE;
break;
}
success = TRUE;
}
if (success) NSLog(#"All Contents Removed");
}
return success;
}
And this is my code in my main program:
NSString *testDir = #"/Users/grinch/MyTestTemp";
//testDir = [NSHomeDirectory() stringByAppendingPathComponent: #"MyTestTemp"];
NSLog(#"testDir is: %#", testDir);
BOOL result = [self deleteDirectoryContents:testDir];
NSLog(#"result is: %d", result);
Here is my console output:
testDir is: /Users/grinch/MyTestTemp
dirEnum in deleteDirectoryContents is <NSAllDescendantPathsEnumerator: 0x60000008c300>
result is: 0
I also checked the value of [dirEnum nextObject] (by uncommenting the NSLog statement in my code). It returns null. And I never see the "filePath is" NSLog statement. So the inner while loop is NEVER executed.
And yes the directory (with files) does exist in my home directory. I created these files. I have permissions. I can easily delete the files in this directory using Finder
What am I missing?
P.S. I did some more testing. It looks like my simple program in Xcode does not have permissions to access files and folders in my home directory. Why? I have no idea.
Here is my additional test code:
NSError *errorMsg;
[[NSFileManager defaultManager] removeItemAtPath:#"/Users/grinch/myTestTemp/Hello.txt" error:&errorMsg];
if (errorMsg) NSLog(#"ERROR - File delete errorMsg is: %#", errorMsg);
success = [[NSFileManager defaultManager] removeItemAtPath:testDir error:&errorMsg];
if (errorMsg) NSLog(#"ERROR - Folder delete errorMsg is: %#", errorMsg);}
And here is my console output:
2022-09-10 09:56:48.958352-0400 NSAlert[97106:7511815] ERROR - File delete errorMsg is: Error Domain=NSCocoaErrorDomain Code=513 "“Hello.txt” couldn’t be removed because you don’t have permission to access it." UserInfo={NSFilePath=/Users/grinch/myTestTemp/Hello.txt, NSUserStringVariant=(
), NSUnderlyingError=0x6040006421f0 {Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"}}
2022-09-10 09:56:48.960560-0400 NSAlert[97106:7511815] ERROR - Folder delete errorMsg is: Error Domain=NSCocoaErrorDomain Code=513 "“MyTestTemp” couldn’t be removed because you don’t have permission to access it." UserInfo={NSFilePath=/Users/grinch/MyTestTemp, NSUserStringVariant=(
), NSUnderlyingError=0x60400045ff80 {Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"}}
So my questions are:
Why didn't the directory enumerator work?
Why doesn't Xcode have the permissions to delete items in my home folder?
How can I give Xcode the the ability (or permissions) to delete items in my home directory?

Answer 1

I have found a bug in my deleteDirectoryContents: method above. And as a result, have answered most of my questions!
First, the statement NSString *filePath = [directoryPath stringByAppendingString:documentsName]; in the while loop will not work. One must insert a / before documentsname. So the line should be NSString *filePath = [directoryPath stringByAppendingFormat:#"/%#",documentsName]; OR even better use NSString *filePath = [directoryPath stringByAppendingPathComponent:documentsName];.
Now the method deleteDirectoryContents: will work as expected.
Here is the code to the fixed method:
- (BOOL) deleteDirectoryContents:(NSString *)directoryPath
{
BOOL success = FALSE;
BOOL isDir;
NSFileManager *fileManager = [NSFileManager defaultManager];
if ([fileManager fileExistsAtPath:directoryPath isDirectory:&isDir] && isDir)
{
NSDirectoryEnumerator *dirEnum = [fileManager enumeratorAtPath:directoryPath];
NSLog(#"dirEnum in deleteDirectoryContents is %#", dirEnum);
NSString *documentsName;
// NSLog(#"[dirEnum nextObject] is: %#", [dirEnum nextObject]);
while (documentsName = [dirEnum nextObject])
{
//NSString *filePath = [directoryPath stringByAppendingFormat:#"/%#",documentsName];
NSString *filePath = [directoryPath stringByAppendingPathComponent:documentsName];
NSLog(#"filePath is: %#", filePath);
NSError *errorMsg = nil;
BOOL isFileDeleted = [fileManager removeItemAtPath:filePath error:&errorMsg];
if (errorMsg) NSLog(#"ERROR - Failed to delete file or folder at: %#. Error message is: %#", filePath, errorMsg);
if(isFileDeleted == NO)
{
NSLog(#"All Contents not removed");
success = FALSE;
break;
}
success = TRUE;
}
if (success) NSLog(#"All Contents Removed");
}
return success;
}
And I can confirm that if your program creates the directory and the files within it, the program can also delete these files using deleteDirectoryContents: while running in the Xcode sandbox DEPENDING on where the folder was originally created.
If the program creates the folder and files in a temporary directory (e.g. caches directory) NOT the users home folder, it works.
But due to Xcode sandboxing,
deleteDirectoryContents: does not appear to work on folder and files created by the program in the users Home directory when running within Xcode.
P.S. I used the following to obtain a temporary directory name:
- (NSString *) get_temporary_dir
{
NSString *path = nil;
NSString *bundleName = [[[NSBundle mainBundle] infoDictionary] objectForKey:#"CFBundleIdentifier"];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
if ([paths count]) {
path = [[paths objectAtIndex:0] stringByAppendingPathComponent:bundleName];
} else {
path = NSTemporaryDirectory();
path = [path stringByAppendingPathComponent:bundleName];
}
return [[[NSString alloc] initWithUTF8String:[path UTF8String]] autorelease];
}
Then the program created the temporary directory using that name. The program created some files in that temporary directory and then was able to delete them using the deleteDirectoryContents: method above.