快速获取文件的别名路径 [英] Getting alias path of file in swift

问题描述

我在Mac上无法解析别名链接.我正在检查文件是否为别名，然后要接收原始路径.相反，我只得到一个File-Id. 安莉的想法?

I'm having trouble resolving the alias link on mac. I'm checking if the file is an alias and then I would want to receive the original path. Instead I'm only getting a File-Id. Anly ideas?

func isFinderAlias(path:String) -> Bool? {

    var isAlias:Bool? = false // Initialize result var.

    // Create a CFURL instance for the given filesystem path.
    // This should never fail, because the existence isn't verified at this point.
    // Note: No need to call CFRelease(fUrl) later, because Swift auto-memory-manages CoreFoundation objects.
    print("path before \(path)");
    let fUrl = CFURLCreateWithFileSystemPath(nil, path, CFURLPathStyle.CFURLPOSIXPathStyle, false)
    print("path furl \(fUrl)");
    // Allocate void pointer - no need for initialization,
    // it will be assigned to by CFURLCopyResourcePropertyForKey() below.
    let ptrPropVal = UnsafeMutablePointer<Void>.alloc(1)

    // Call the CoreFoundation function that copies the desired information as
    // a CFBoolean to newly allocated memory that prt will point to on return.
    if CFURLCopyResourcePropertyForKey(fUrl, kCFURLIsAliasFileKey, ptrPropVal, nil) {

        // Extract the Bool value from the memory allocated.
        isAlias = UnsafePointer<CFBoolean>(ptrPropVal).memory as Bool


        // it will be assigned to by CFURLCopyResourcePropertyForKey() below.
        let ptrDarwin = UnsafeMutablePointer<DarwinBoolean>.alloc(1)

        if ((isAlias) == true){
            if let bookmark = CFURLCreateBookmarkDataFromFile(kCFAllocatorDefault, fUrl, nil){
                let url = CFURLCreateByResolvingBookmarkData(kCFAllocatorDefault, bookmark.takeRetainedValue(), CFURLBookmarkResolutionOptions.CFBookmarkResolutionWithoutMountingMask, nil, nil, ptrDarwin, nil)
                print("getting the path \(url)")
            }
        }

        // Since the CF*() call contains the word "Copy", WE are responsible
        // for destroying (freeing) the memory.
        ptrDarwin.destroy()
        ptrDarwin.dealloc(1)
        ptrPropVal.destroy()
    }

    // Deallocate the pointer
    ptrPropVal.dealloc(1)

    return isAlias
}

两个答案都是正确的！ 我之所以选择mklement0的答案，是因为最初没有说明该代码必须在10.9上运行，从而使其更加灵活

Both Answers are correct! I would choose the answer of mklement0 due to the originally not stated requirement that the code run on 10.9 which makes it more flexible

推荐答案

vadian的答案在 OS上效果很好X 10.10 + .

这是一个实现，也可以在OS X 10.9 上使用:

// OSX 10.9+
// Resolves a Finder alias to its full target path.
// If the given path is not a Finder alias, its *own* full path is returned.
// If the input path doesn't exist or any other error occurs, nil is returned.
func resolveFinderAlias(path: String) -> String? {
  let fUrl = NSURL(fileURLWithPath: path)
  var targetPath:String? = nil
  if (fUrl.fileReferenceURL() != nil) { // item exists
    do {
        // Get information about the file alias.
        // If the file is not an alias files, an exception is thrown
        // and execution continues in the catch clause.
        let data = try NSURL.bookmarkDataWithContentsOfURL(fUrl)
        // NSURLPathKey contains the target path.
        let rv = NSURL.resourceValuesForKeys([ NSURLPathKey ], fromBookmarkData: data) 
        targetPath = rv![NSURLPathKey] as! String?
    } catch {
        // We know that the input path exists, but treating it as an alias 
        // file failed, so we assume it's not an alias file and return its
        // *own* full path.
        targetPath = fUrl.path
    }
  }
  return targetPath
}

注意:

• 与vadian的解决方案不同，即使对于 non -alias文件，这也将返回一个值，即该文件的 own 完整路径，并采用路径字符串而不是NSURL实例作为输入.

• Unlike vadian's solution, this will return a value even for non-alias files, namely that file's own full path, and takes a path string rather than a NSURL instance as input.

vadian的解决方案需要适当的权利才能在沙盒应用程序/环境中使用该功能. 似乎认为这至少不需要相同程度的 ，因为它将运行在 Xcode Playground ，与vadian的解决方案不同. ^{如果有人可以阐明这一点，请提供帮助.}

vadian's solution requires appropriate entitlements in order to use the function in a sandboxed application/environment. It seems that this one at least doesn't need that to the same extent, as it will run in an Xcode Playground, unlike vadian's solution. ^{If someone can shed light on this, please help.}

• 但是，这两种解决方案都可以在 shell脚本中使用shebang行#!/usr/bin/env swift来运行.

• Either solution, however, does run in a shell script with shebang line #!/usr/bin/env swift.

如果您要明确测试是否给定路径是Finder别名，请参见此答案，源自vadian的答案，但由于其关注范围较窄，因此也适用于10.9.

If you want to explicitly test whether a given path is a Finder alias, see this answer, which is derived from vadian's, but due to its narrower focus also runs on 10.9.

这篇关于快速获取文件的别名路径的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！