If the user moves a file in the Finder, any path-based URLs that refer to the file immediately become invalid and must be updated to the new path. However, as long as the file moved to another location on the same disk, its unique ID does not change and any file reference URLs remain valid. Of course, there are still times when you might need to use strings to refer to a file. You might use a string-based path when presenting that path to the user or when calling a system routine that accepts strings instead of URLs.
Neither class attempts to validate the actual existence of the file or directory you specify. In fact, you must create the path to a nonexistent file or directory before you can create it on disk. If you have an NSURL object that refers to an actual file or directory on disk, and you want to get the user visible name of the volume on which it resides, you use the method getResourceValue:forKey:error: in a two step process:.
Listing Obtaining the user visible volume name for a resource URL. Before you can access a file or directory, you need to know its location. There are several ways to locate files and directories:. The file systems of iOS and macOS impose specific guidelines on where you should place files, so most of the items your app creates or uses should be stored in a well-known place.
Both systems provide interfaces for locating items in such well-known places, and your app can use these interfaces to locate items and build paths to specific files. An app should prompt the user to specify the location of a file or directory only in a limited number of situations that are described in Using the Open and Save Panels.
In macOS, user interactions with the file system should always be through the standard Open and Save panels. Because these panels involve interrupting the user, use them only in a limited number of situations:. Never use the Open and Save panels to access any files that your app created and uses internally. Support files, caches, and app-generated data files should be placed in one of the standard directories dedicated to app-specific files.
Apps that need to locate resource files inside their bundle directory or inside another known bundle must do so using an NSBundle object. Bundles eliminate the need for your app to remember the location of individual files by organizing those files in a specific way. The advantage of this technique is that you can generally rearrange the contents of your bundle without rewriting the code you use to access it.
This code determines only the location of the file; it does not open the file. You would pass the returned URL to a method of the NSImage class to load the image from disk so that you could use it. For more information about bundles, including how to locate items in a bundle, see Bundle Programming Guide. For specific information about loading and using resources in your app, see Resource Programming Guide. When you need to locate a file in one of the standard directories, use the system frameworks to locate the directory first and then use the resulting URL to build a path to the file.
The Foundation framework includes several options for locating the standard system directories. By using these methods, the paths will be correct whether your app is sandboxed or not:. Which home directory is returned depends on the platform and whether the app is in a sandbox. You can use the URL or path-based string you receive from the preceding routines to build new objects with the locations of the files you want. Listing Creating a URL for an item in the app support directory.
A bookmark is an opaque data structure, enclosed in an NSData object, that describes the location of a file. Whereas path- and file reference URLs are potentially fragile between launches of your app, a bookmark can usually be used to re-create a URL to a file even in cases where the file was moved or renamed.
Listing shows a simple example implementation that uses this method to create a bookmark data object. Listing Converting a URL to a persistent form.
Aliases are similar to symbolic links but are implemented differently. Normally, users create aliases from the Finder when they want to create links to files elsewhere on the system.
Listing shows the process for converting a bookmark back into a URL. Listing Returning a persistent bookmark to its URL form. To discover the contents of a given directory, you enumerate that directory.
Cocoa supports enumerating a directory one file at a time or all at once. Regardless of which option you choose, enumerate directories sparingly. Each enumeration can touch a large number of files and subdirectories. This quickly becomes expensive. Enumerating a directory one file at a time is recommended when you want to search for a specific file and stop enumerating when you find it.
File-by-file enumeration uses the NSDirectoryEnumerator class, which defines the methods for retrieving items. Because NSDirectoryEnumerator itself is an abstract class, however, you do not create instances of it directly. Enumerator objects return the paths of all files and directories contained within the enumerated directory. Because enumerations are recursive and cross device boundaries, the number of files and directories returned may be more than what is present in the starting directory.
Enumerator objects do not resolve symbolic links or attempt to traverse symbolic links that point to directories. Listing shows how to use the enumeratorAtURL:includingPropertiesForKeys:options:errorHandler: method to list all the user-visible subdirectories of a given directory, noting whether they are directories or file packages.
The keys array tells the enumerator object to prefetch and cache information for each item. Prefetching this information improves efficiency by touching the disk only once. The options argument specifies that the enumeration should not list the contents of file packages and hidden files. The error handler is a block object that returns a Boolean value. If the block returns YES , the enumeration continues after the error; if it returns NO , the enumeration stops.
Listing Enumerating the contents of a directory. You can use other methods declared by NSDirectoryEnumerator to determine attributes of files during the enumeration—both of the parent directory and the current file or directory—and to control recursion into subdirectories.
The code in Listing enumerates the contents of a directory and lists files that have been modified within the last 24 hours; if, however, it comes across RTFD file packages, it skips recursion into them. If you do not have the appropriate permission, you can't access or change files or folders. So if Windows denies your access to a certain file or folder, you get the permission of the file or folder in following steps.
First of all, you need to check permissions on a file or a folder. Here we'll show you a simple tutorial below. Click on your name in "Group or user names" to check the permission that you have. If you want to change the permissions on a file or a folder, you should log on the PC as an administrator. Next, click on "Edit" in "Security" tab. And then, choose your name and enable the check boxes of the permissions that you need.
File encryption has the ability to protect users' files and folders. Moreover, if a file is encrypted, you need the certificate that used to encrypt it to open the encrypted file or folder. Otherwise, you may get the "Access Denied" error. To check encrypted file or folder, follow these steps. After that, you can check if "Encrypt Content to Secure Data" option is enabled.
If it is checked, you will need the certificate to open or the file or folder. If "Encrypt Content to Secure Data" option is unchecked, the file or folder is not encrypted. It takes just a few simple steps to recover the corrupted file or folder. Next, you can launch the software to check if it's successfully running on your PC. Hint: You may want to install data recovery on a partition that doesn't contain the data you want to recover. Otherwise, the installation could overwrite the data. If the software is successfully running, you are able to select the files types you need on the main interface.
Files types like image, video, audio, email, document are available to restore. What is program data folder in Windows 10? How to access program data folder? Why is program data folder missing in Windows 10? Check the answers in this post. To recover deleted or lost files, folders, photos, videos, etc. The installed programs may store the program data in different places on your computer.
The Program Data folder is alike the Application Data folder. However, the ProgramData folder in C drive on your Windows computer is used for storing application data that is not user-specific. Windows 10 Program Data folder is shared among all the user accounts on your Windows 10 computer. On the contrary, the Application Data folder is user-specific, and it has an individual folder for each user on your PC.
The Program Data folder in Windows 10 is an important system folder. If you change the default location of its location, the updates, fixes, or service packs of this program may not be applied. If your computer is running out of space, you have some other ways to clean up disk space. Generally, it is hidden by default.
Check how to show hidden files and folders in Windows 10 to reveal Windows Program Data folder below. This should unhide the ProgramData folder in your Windows 10 computer if it is hidden before.
You can then find and view Windows 10 ProgramData folder in the C drive.
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