In any scenario can app have multiple paths in NSArray when accessing NSDocumentDirectory using following code :
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
I am just curious about thing..can you all share your experience with me?
Strictly spoken you can get multiple paths because you can pass multiple domains.
If you pass a single domain you get an array containing a single path.
However Apple recommends not to use this function anymore.
From the documentation:
You should consider using the NSFileManager methods URLsForDirectory:inDomains: and URLForDirectory:inDomain:appropriateForURL:create:error: which return URLs, which are the preferred format.
No this will always return one path for documentDirectory!!
It may vary as per different kind of directory like,
NSString *path = NSTemporaryDirectory();
above line will give temp directory's path.
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory, NSUserDomainMask, YES);
above array have also one path but this is path of NSDocumentationDirectory.
NSSearchPathForDirectoriesInDomains Creates a list of path strings for the specified directories in the specified domains. The list is in the order in which you should search the directories.
You can get content or sub directory of document directory or any directory like,
NSArray *pathArr = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSAllDomainsMask, YES);
NSArray *contentOfDocDirectory = [[NSFileManager defaultManager]contentsOfDirectoryAtPath:pathArr[0] error:nil];
NSLog(#"content of document directory : %#",contentOfDocDirectory);
Related
I am trying to take content from one file and write it into another. I am reading fine, but I am not able to write it into another file.
I have a database of words. I want to separate the words into different files based on the number of letters. All four letter words go into one file, and so on. I added a txt file called "4letter" into my resources and the following is my code:
NSError *error;
//READ
NSString *dbFile = [[NSBundle mainBundle] pathForResource:#"words" ofType:#"txt"];
NSString *test = [NSString stringWithContentsOfFile:dbFile encoding:NSUTF8StringEncoding error:&error];
//convert from string to array
NSArray *lines = [test componentsSeparatedByString:#"\n"];
NSFileHandle *logFile = nil;
logFile = [NSFileHandle fileHandleForWritingAtPath:[[NSBundle mainBundle] pathForResource:#"4letter" ofType:#"txt"]];
//Test if write works
for (int i=0; i<5; i++)
{
NSString *randomAnagram = [[lines objectAtIndex:i] lowercaseString];
[logFile writeData: [randomAnagram dataUsingEncoding: NSNEXTSTEPStringEncoding]];
}
In iOS, you can't write into a file in your app's bundle -- the entire bundle is read-only. Use a path into the Documents folder instead.
See special File System Programming Guide for better understnading.
In iOS, you can't write into a file in your app's bundle -- the entire bundle is read-only.
Consider reading iOS Data Storage Guidelines to better understand the purpose of directories below, in context of iCloud backup.
<Application_Home>/AppName.app
This is the bundle directory containing the app itself. Do not write
anything to this directory. To prevent tampering, the bundle directory
is signed at installation time. Writing to this directory changes the
signature and prevents your app from launching again.
<Application_Home>/Documents/
Use this directory to store critical user documents and app data
files. Critical data is any data that cannot be recreated by your app,
such as user-generated content. The contents of this directory can be
made available to the user through file sharing. The contents of this
directory are backed up by iTunes.
<Application_Home>/Library/
This directory is the top-level directory for files that are not user
data files. You typically put files in one of several standard
subdirectories but you can also create custom subdirectories for files
you want backed up but not exposed to the user. You should not use
this directory for user data files. The contents of this directory
(with the exception of the Caches subdirectory) are backed up by
iTunes. For additional information about the Library directory, see
“The Library Directory Stores App-Specific Files.”
See full list (tmp/, Documents/Inbox) in iOS Standard Directories: Where Files Reside
UPDATE
I use NSFileManager method URLForDirectory:inDomain:appropriateForURL:create:error:
Like Caleb said, you can't write to your app's directory, but you can write to your app's Documents folder. You can get it like this:
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
Your app's bundle is read-only. There is two ways I could see:
1) Write in documents folder:
NSArray *pathList = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *path = [myPathList objectAtIndex:0];
2) Use sqlite database. This is the same as 1 (you must save db in documents anyway), but you're using sqlite database. I think this is better than a lot of txt and plist files: here's a tutorial on the topic.
I use the following code :
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *appFile = [documentsDirectory stringByAppendingPathComponent:#"set.txt"];
NSString *data=#"Kostas";
[data writeToFile:appFile atomically:YES];
NSString *myData = [NSString stringWithContentsOfFile:appFile];
NSLog(#"Data : %# ",myData);
I am trying to take content from one file and write it into another. I am reading fine, but I am not able to write it into another file.
I have a database of words. I want to separate the words into different files based on the number of letters. All four letter words go into one file, and so on. I added a txt file called "4letter" into my resources and the following is my code:
NSError *error;
//READ
NSString *dbFile = [[NSBundle mainBundle] pathForResource:#"words" ofType:#"txt"];
NSString *test = [NSString stringWithContentsOfFile:dbFile encoding:NSUTF8StringEncoding error:&error];
//convert from string to array
NSArray *lines = [test componentsSeparatedByString:#"\n"];
NSFileHandle *logFile = nil;
logFile = [NSFileHandle fileHandleForWritingAtPath:[[NSBundle mainBundle] pathForResource:#"4letter" ofType:#"txt"]];
//Test if write works
for (int i=0; i<5; i++)
{
NSString *randomAnagram = [[lines objectAtIndex:i] lowercaseString];
[logFile writeData: [randomAnagram dataUsingEncoding: NSNEXTSTEPStringEncoding]];
}
In iOS, you can't write into a file in your app's bundle -- the entire bundle is read-only. Use a path into the Documents folder instead.
See special File System Programming Guide for better understnading.
In iOS, you can't write into a file in your app's bundle -- the entire bundle is read-only.
Consider reading iOS Data Storage Guidelines to better understand the purpose of directories below, in context of iCloud backup.
<Application_Home>/AppName.app
This is the bundle directory containing the app itself. Do not write
anything to this directory. To prevent tampering, the bundle directory
is signed at installation time. Writing to this directory changes the
signature and prevents your app from launching again.
<Application_Home>/Documents/
Use this directory to store critical user documents and app data
files. Critical data is any data that cannot be recreated by your app,
such as user-generated content. The contents of this directory can be
made available to the user through file sharing. The contents of this
directory are backed up by iTunes.
<Application_Home>/Library/
This directory is the top-level directory for files that are not user
data files. You typically put files in one of several standard
subdirectories but you can also create custom subdirectories for files
you want backed up but not exposed to the user. You should not use
this directory for user data files. The contents of this directory
(with the exception of the Caches subdirectory) are backed up by
iTunes. For additional information about the Library directory, see
“The Library Directory Stores App-Specific Files.”
See full list (tmp/, Documents/Inbox) in iOS Standard Directories: Where Files Reside
UPDATE
I use NSFileManager method URLForDirectory:inDomain:appropriateForURL:create:error:
Like Caleb said, you can't write to your app's directory, but you can write to your app's Documents folder. You can get it like this:
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
Your app's bundle is read-only. There is two ways I could see:
1) Write in documents folder:
NSArray *pathList = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *path = [myPathList objectAtIndex:0];
2) Use sqlite database. This is the same as 1 (you must save db in documents anyway), but you're using sqlite database. I think this is better than a lot of txt and plist files: here's a tutorial on the topic.
I use the following code :
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *appFile = [documentsDirectory stringByAppendingPathComponent:#"set.txt"];
NSString *data=#"Kostas";
[data writeToFile:appFile atomically:YES];
NSString *myData = [NSString stringWithContentsOfFile:appFile];
NSLog(#"Data : %# ",myData);
I'm using NSFileManager and i'm trying to copy a file to path "/var/mobile/Applications/7AC2295E-2775-41EA-B017-AB4048A09F0C/Document" the file will copy fine.
but the path of "7AC2295E-2775-41EA-B017-AB4048A09F0C" is randomly changed in every time i delete and install the app again. So, is there a way to get the correct path of my app or search for file name, If file exist then replace\delete..etc the file? thanks alot.
The proper way to get access to the Documents directory in your app's sandbox is:
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = paths[0];
Then you create your path:
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:#"filename.ext"];
You don't have to use the absolute path, use something like
NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)objectAtIndex:0];
[[NSFileManager defaultManager] copyItemAtPath:[[NSBundle mainBundle]pathForResource:#"test" ofType:#"txt"] toPath:[documentsDirectory stringByAppendingPathComponent:#"test.txt"] error:nil];
This demonstrates copying the file test.txt from the apps bundle to the documents directory.
Do something like this to create a file test.txt
[[NSFileManager defaultManager] createFileAtPath:[documentsDirectory stringByAppendingPathComponent:#"test.txt"] contents:[NSData dataWithContentsOfURL:[NSURL URLWithString:#"http://a-cstudios.com/text.json"]] attributes:nil];
EDIT
If your using this and want to use it on a jailbroken device, to put something in the sandbox is the same as I said before, so you still don't have to use the UUID. If you want to put something in a system directory, that is when you would use something like /usr/include/, or wherever you want to. To put something in another apps sandbox, you would have to use the complete path, and you would have to know the UUID, as thats not part of your sandbox. So, unless you're copying a file to an app that you made, you have to use the complete path.
If your application needs to write a file to its Documents directory.
use something like :
NSString *filePath = NSHomeDirectory();
then append your actual file name to filePath.
then use filePath in your FileManager calls.
-[NSFileManager URLForDirectory:inDomain:appropriateForURL:create:error:] requires a single NSSearchPathDomainMask and returns a single URL. (The ...appropriateForURL:create:error: part is a bit confusing in documentation.)
-[NSFileManager URLsForDirectory:inDomains:] allows you to create a bit-mask for the domains parameter and returns an array of URLs.
It seems to me there is overlap between these two methods. If my goal is to get the Documents, or Library, or etc directory from an iOS app's sandbox, when should I use one over the other?
The standard way to get access to the Documents directory (or other similar directories) is code like the following:
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = paths[0];
This is similar to doing:
NSArray *URLs = [[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask];
NSURL *documentsURL = URLs[0];
The key difference is the first gives you the path as an NSString while the second gives you the path as an NSURL.
The other method can be used by doing:
NSURL *documentsURL = [[NSFileManager defaultManager] URLForDirectory:NSDocumentDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:NO error:nil];
You can pass NO for the Documents directory because it always exists. You should pass YES for the application support directory since it doesn't exist by default. And ideally you should not pass in nil for the error so you can see what happened if the method call returns nil.
Any of these three approaches work. Use the 1st if you want the path as a string. Use the 3rd if you want it as a URL. Use the 2nd if you have the rare need to pass in more than one domain.
My app allows users to create and delete files from the documents folder within the app. They can do it through the app itself or manually using itunes. Is there are way to access what's left in the documents folder without any hardcoding of the filenames?
Thank you.
You can get NSArray with all items in given directory using contentsOfDirectoryAtPath:error: method in NSFileMamanger:
NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSArray *allItems = [[NSFileManager sharedFileManager] contentsOfDirectoryAtPath:documentsDirectory error:NULL];