快速获取文件的别名路径

Question

我在解析Mac上的别名链接时遇到问题。我正在检查文件是否是别名，然后我想接收原始路径。相反，我只得到一个文件ID。安莉的想法？

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
}

编辑： 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

Answer 1

这是 在OS X 10.9上也可以 使用的 实现 ：

// 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 非 别名文件，这也将返回一个值，即该文件 自己的 完整路径，并且将路径字符串而不是NSURL实例作为输入。

• 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。它 似乎 ，这其中至少不需要那么 在相同的程度 ，因为它 会 在运行 Xcode的游乐场 ，不像vadian的解决方案。如果有人可以阐明这一点，请帮助。

  • 但是，这两种解决方案 都 可以在带有shebang line 的 shell脚本 中 运行#!/usr/bin/env swift。