如何在 OS X 中移动文件并创建丢失的目录？

Question

我想将 OSX 中的文件移动到另一个目录：

func moveFile(currentPath currentPath: String, targetPath: String) {

let fileManager = NSFileManager.defaultManager()

do { try fileManager.moveItemAtPath(currentPath, toPath: targetPath) }
catch let error as NSError { print(error.description) }

}

一切正常，除了目标目录不存在的情况。我发现 .isWritableFileAtPath 可能会有帮助。

但是，在我声明的函数中，我使用了完整的文件路径（包括文件名）。

一般情况下如何从路径或更多路径中拆分文件名：如果需要，我如何强制Swift在移动文件之前创建目录？

Answer 1

过去我用类似于下面代码的代码解决了这个问题。基本上，您只需检查代表您要创建的文件的父目录的路径中是否存在文件。如果它不存在，您将创建它，并在不存在的路径中创建它上面的所有文件夹。

func moveFile(currentPath currentPath: String, targetPath: String) {
    let fileManager = NSFileManager.defaultManager()
    let parentPath = (targetPath as NSString).stringByDeletingLastPathComponent()
    var isDirectory: ObjCBool = false
    if !fileManager.fileExistsAtPath(parentPath, isDirectory:&isDirectory) {
        fileManager.createDirectoryAtPath(parentPath, withIntermediateDirectories: true, attributes: nil)

        // Check to see if file exists, move file, error handling
    }
    else if isDirectory {
        // Check to see if parent path is writable, move file, error handling
    }
    else {
        // Parent path exists and is a file, error handling
    }
}

您可能还想使用 fileExistsAtPath:isDirectory: 变体，以便处理其他错误情况。

也是如此

Answer 2

我已将此扩展添加到 FileManager 以实现此目的

extension FileManager {

    func moveItemCreatingIntermediaryDirectories(at: URL, to: URL) throws {
        let parentPath = to.deletingLastPathComponent()
        if !fileExists(atPath: parentPath.path) {
            try createDirectory(at: parentPath, withIntermediateDirectories: true, attributes: nil)
        }
        try moveItem(at: at, to: to)
    }

}

Answer 3

添加这个是因为这个问题在 Google 中弹出，而其他答案使用的 API 在这种情况下可能不应该。

请务必在 FileExists(atPath:) 文档中注意这一点：

Attempting to predicate behavior based on the current state of the file system or a particular file on the file system is not recommended. Doing so can cause odd behavior or race conditions. It’s far better to attempt an operation (such as loading a file or creating a directory), check for errors, and handle those errors gracefully than it is to try to figure out ahead of time whether the operation will succeed. For more information on file-system race conditions, see Race Conditions and Secure File Operations in Secure Coding Guide.

此外，来自 createDirectory(atPath:withIntermediateDirectories:attributes:) 文档：

Return Value

true if the directory was created, true if createIntermediates is set and the directory already exists, or false if an error occurred.

在 withIntermediateDirectories: 参数设置为 true 的情况下尝试创建一个新目录，如果该目录已经存在，则不会抛出错误，因此即使该目录已经存在，您也可以安全地使用它。

跳过存在检查，尝试写入目录，然后尝试移动文件：


func moveFile(from currentURL: URL, to targetURL: URL) {

    // Get the target directory by removing the file component
    let targetDir = targetURL.deletingLastPathComponent()

    do {
        try FileManager.default.createDirectory(at:targetDir, withIntermediateDirectories: true, attributes: nil)
    } catch {
        // Handle errors
    }
    do { 
        try FileManager.default.moveItem(at:currentURL, to: targetURL) }
    catch { 
        // Handle errors
    }
}

如何在 OS X 中移动文件并创建丢失的目录？

How to move a file and create missing directories in OS X?

macos

cocoa

nsfilemanager

swift2