Swift basic FileManager (file management)

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Preface

Swift Basics FileManager( file management ) Download link

FileManager It is inevitable to use in project development , for example ： I'm developing company music app You will need to save the downloaded songs . So record it today FileManager Use .

On the subject

1、 obtain Documentation Directory path

The most basic thing of file management is to get the directory of files , Get the directory of the file , The method to be called is the scope to be searched later .

open func urls(for directory: FileManager.SearchPathDirectory, in domainMask: FileManager.SearchPathDomainMask) -> [URL]

The system provides us with two important parameters ：
directory： The name of the file to search
domainMask： Search in that fuzzy range

for example ：

// TODO:  obtain  Documentation  Directory path 
let domainsArray = FileManager.default.urls(for:.documentDirectory, in: .userDomainMask)
let domainsPath = domainsArray[0] as URL
print(domainsPath)

The following provides the file box simulation path commonly used for searching

1.1. SearchPathDirectory Optional parameters for searching directories

 applicationDirectory ：  stay  applications  Search under directory .
 demoApplicationDirectory ：  stay  applications/Demo  Search under the directory of .
 developerApplicationDirectory ：  stay  Developer/Applications  Search under directory .
 adminApplicationDirectory ：  stay  Applications/Utilities  Search under directory .
 libraryDirectory ： stay  Library  Search under directory .
 developerDirectory ：  stay  Developer  Search under directory , Not just a developer .
 userDirectory ：  Search under the user's home directory .
 documentationDirectory ：  stay  Documentation  Search under directory .
 documentDirectory :  stay  Documents  Search under directory .
 coreServiceDirectory ：  stay  System/Library/CoreServices  Search under directory .
 autosavedInformationDirectory ：  Auto saved document location search  （Documents/Autosaved）
 desktopDirectory ：  Search the user desktop .
 cachesDirectory ：  Search in the local buffer directory （Library/Caches）
 applicationSupportDirectory ： Search under directories supported by local applications （Library/Application Support）.
 downloadsDirectory ：  Download locally downloads Catalog .
 inputMethodsDirectory ： Search under the input method directory （Library/Input Methods）.
 moviesDirectory ：  Search the user movie directory （~/Movies）.
 musicDirectory ：  Search the user's music directory （~/Music）.
 picturesDirectory：  Search in the user image directory （~/Pictures）.
 printerDescriptionDirectory ：  Local to the system PPDs Search under directory （Library/Printers/PPDs）.
 sharedPublicDirectory ：  Search under the local user sharing directory （~/Public）.
 preferencePanesDirectory ：  Search in the preferences directory of the system （Library/PreferencePanes）.
 itemReplacementDirectory ： For use with NSFileManager's URLForDirectory:inDomain:appropriateForURL:create:error:
 allApplicationsDirectory ： Apply all paths that can happen  .
 allLibrariesDirectory ：  All directories where resources can occur  .

1.2. SearchPathDomainMask Optional parameters of fuzzy search in path field

 userDomainMask ：    User's home directory path domain search .
 localDomainMask ：   Current device local path domain search .
 networkDomainMask ： Path domain search of network sharing .
 systemDomainMask ：  System path domain search provided by Apple .
 allDomainsMask ：    Path field search for all the above situations .

2、 Get the file name under the path

let homePath = NSHomeDirectory()
// TODO:  Get the file name under the path 
let contentsOfPath = try? FileManager.default.contentsOfDirectory(atPath: homePath + "/Documents")
print(contentsOfPath as Any)
/**  Output results ： Optional(["music", ".DS_Store", "fenghanxu", "downloads"]) */

The search results shown in the figure below

3、 Get the path of all files under the specified path URL

// TODO:  Get the path of all files under the specified path URL
let contentsOfUrl = try? FileManager.default.contentsOfDirectory(at: URL.init(string: NSHomeDirectory() + "/Documents")!, includingPropertiesForKeys: [URLResourceKey.creationDateKey], options: .skipsSubdirectoryDescendants)
print(contentsOfUrl as Any)

4、 Depth traversal of all files under the specified path

// TODO:  Depth traversal of all files under the specified path 
let allFiel = FileManager.default.enumerator(atPath: NSHomeDirectory() + "/Documents")
print(allFiel?.allObjects as Any)
/**  Output results ：Optional([music, music/.DS_Store, music/javaScript.html, .DS_Store, fenghanxu, fenghanxu/.DS_Store, fenghanxu/xxx.dmg, downloads, downloads/.DS_Store, downloads/arm64.dmg]) */

perhaps

//  Another way to traverse files in depth 
let subPath = FileManager.default.subpaths(atPath: NSHomeDirectory() + "/Documents")
print(subPath as Any)
/**  Output result ： Optional([music, music/xxx.dmg, .DS_Store, fenghanxu, fenghanxu/.DS_Store, fenghanxu/xxx.dmg, downloads, downloads/.DS_Store, downloads/arm64.dmg]) */

5、 Convert the specified file into Data Binary stream data

// TODO:  Convert the specified file into  Data  Binary stream data 
let data = FileManager.default.contents(atPath: NSHomeDirectory() + "/Documents/fenghanxu/xxx.dmg")
print(data!)
/**  Output results ：Optional("12308244 bytes") */

6、 create a file

// TODO:  create a file 
let isFile = FileManager.default.createFile(atPath: NSHomeDirectory() + "/Documents/MyFile", contents: nil, attributes: nil)
print(isFile)
/**  Output results ： true  Indicates that the creation was successful  ; false  Indicates creation failed  */

The following picture is the result of printing ：

Here is the effect ：

let data = "i love swift".data(using: .utf8)
let isFile = FileManager.default.createFile(atPath: NSHomeDirectory() + "/Documents/MyFile.txt", contents: data, attributes: nil)
print(isFile)
/**  Output results ： true  Indicates that the creation was successful  ; false  Indicates creation failed  */

The following picture is the result of printing ：

Here is the effect ：

7、 Judge whether the file exists

// TODO:  Judge whether the file exists 
var isSave = FileManager.default.fileExists(atPath: NSHomeDirectory() + "/Documents/MyFile.txt")
print(isSave)

var directory = ObjCBool(true)
isSave = FileManager.default.fileExists(atPath: NSHomeDirectory() + "/Documents/MyFile.txt", isDirectory: &directory)
print(isSave)
/**  Output results ： true  Indicates presence  ; false  Does not exist  */

8、 Determine file permissions

// TODO:  Determine whether the file is readable 
let isRead = FileManager.default.isReadableFile(atPath: NSHomeDirectory() + "/Documents/MyFile.txt")
print("isRead: \(isRead)")//isRead: true

// TODO:  Judge whether the document is writable 
let isWrite = FileManager.default.isWritableFile(atPath: NSHomeDirectory() + "/Documents/MyFile.txt")
print("isWrite: \(isWrite)")//isWrite: true

// TODO:  Determine whether the file is an executable file 
let isExecutable = FileManager.default.isExecutableFile(atPath: NSHomeDirectory() + "/Documents/MyFile.txt")
print("isExecutable: \(isExecutable)")//isExecutable: false

// TODO:  Judge whether the file can be deleted 
let isDele = FileManager.default.isDeletableFile(atPath: NSHomeDirectory() + "/Documents/MyFile.txt")
print("isDele: \(isDele)")//isDele: true

9、 Get the local name of the file and the name set of all paths of the file

// TODO:  Return the local display name of the file 
let disName = FileManager.default.displayName(atPath: NSHomeDirectory() + "/Documents/MyFile.txt")
print(disName)

// TODO:  Get the names of all files in the path 
let componentsDisName = FileManager.default.componentsToDisplay(forPath: NSHomeDirectory() + "/Documents")
print(componentsDisName as Any)
/**  Output results ： Optional(["edy -  data ", "Users", "edy", "Library", "Developer", "CoreSimulator", "Devices", "792DE238-7207-4A66-AB82-9E5BFEE2EF8F", "data", "Containers", "Data", "Application", "108D7874-63DC-4F14-BFBF-E176E1793520", "Documents"]) */

10 、 Write and save data

// MARK:  The writing of file data 
let info = "i love swift"
try! info.write(toFile: NSHomeDirectory() + "/Documents/MyFile.txt", atomically: true, encoding: .utf8)

// MARK:  Save the array 
let arraySave = NSArray.init(arrayLiteral: "a","b","c")
arraySave.write(toFile: NSHomeDirectory() + "/Documents/MyFilePlist.plist", atomically: true)

// MARK:  Save the dictionary 
let dictionSave = NSDictionary.init(dictionaryLiteral: ("A","ccc"),("B","bb"),("C","bbx"))
dictionSave.write(toFile: NSHomeDirectory() + "/Documents/MyFilePlist.plist", atomically: true)

// MARK:  take Data  preservation 
let imagData = UIImage.init(named: "example.jpg")!.pngData()
try? imagData?.write(to: URL.init(fileURLWithPath: NSHomeDirectory() + "/Documents/MyPicture.jpg"))

11 、 Copy of documents 、 Move 、 Delete 、 Read operation

// MARK:  Copy of documents ( Be careful ： The file to be copied , If there is . Copy will fail )
let startFilePath = NSHomeDirectory() + "/Documents/MyFile.txt"
let toFilePath = NSHomeDirectory() + "/Documents/MyFileCopy.txt"
try? FileManager.default.copyItem(at:URL.init(fileURLWithPath: startFilePath) , to: URL.init(fileURLWithPath: toFilePath))

// MARK:  File movement 
let MoveStartFilePath = NSHomeDirectory() + "/Documents/MyFileCopy.txt"
let MoveToFilePath = NSHomeDirectory() + "/Documents/test/MyFileCopy.txt"
try? FileManager.default.moveItem(atPath: MoveStartFilePath, toPath: MoveToFilePath)

// MARK:  Delete file 
let DeleFilePath  = NSHomeDirectory() + "/Documents/test/MyFileCopy.txt"
try! FileManager.default.removeItem(atPath: DeleFilePath)

// MARK:  Data reading 
let readDataPath = NSHomeDirectory() + "/Documents/MyFile.txt"
let dataInfo = FileManager.default.contents(atPath: readDataPath)
let readStr = String.init(data: dataInfo!, encoding: .utf8)
print(readStr!)

Print the results ：

12 、 Get file attributes and basic file information

// MARK:  Get the properties of the file 
let attributes = try! FileManager.default.attributesOfFileSystem(forPath: NSHomeDirectory() + "/Documents/MyFile.txt")
print(attributes)
/**  Output results  [__C.NSFileAttributeKey(_rawValue: NSFileSystemFreeNodes): 224441360, __C.NSFileAttributeKey(_rawValue: NSFileSystemSize): 250685575168, __C.NSFileAttributeKey(_rawValue: NSFileSystemNumber): 16777220, __C.NSFileAttributeKey(_rawValue: NSFileSystemFreeSize): 22982795264, __C.NSFileAttributeKey(_rawValue: NSFileSystemNodes): 228901731] */
//  Get some basic information about files 
let CreateData = attributes[FileAttributeKey.creationDate]
let FileSzie =  attributes[FileAttributeKey.systemSize]
print(CreateData as Any)// nil
print(FileSzie as Any)// Optional(250685575168)

13、 Get the path of the current domain and change the file path ( No effect )

// MARK:  Get the current path of the file 
let CurrentPath = FileManager.default.currentDirectoryPath
print(CurrentPath)

// MARK:  Change of file path 
let exchangePath = "Documents"
let  isExchangePath = FileManager.default.changeCurrentDirectoryPath(exchangePath)
print(isExchangePath)

14 、 Comparison of files or folders

Just go back to true. Not the same false

// MARK:  Comparison of documents 
let  oneFilePath = NSHomeDirectory() + "/Documents/MyFile.txt"
let  otherFilePath = NSHomeDirectory() + "/Documents/MyFilePlist.plist"
let isEqual = FileManager.default.contentsEqual(atPath: oneFilePath, andPath: otherFilePath)
print(isEqual)

Just go back to true. Not the same false

//  Folder comparison 
let FilePath = NSHomeDirectory() + "/Documents/test"
let FilePathOne = NSHomeDirectory() + "/Documents/test1"
let isEqualFile = FileManager.default.contentsEqual(atPath: FilePath, andPath: FilePathOne)
print(isEqualFile)