如何使用 Swift 获取 DispatchIO 的文件描述符？

Question

我正在尝试将下面的 Objective-C 代码转换为 Swift。

-(void)openChannelWithURL:(NSURL*)anURL {
   NSString* filePath = [anURL path];
   self.channel = dispatch_io_create_with_path(DISPATCH_IO_RANDOM,
                      [filePath UTF8String],   // Convert to C-string
                      O_RDONLY,                // Open for reading
                      0,                       // No extra flags
                      dispatch_get_main_queue(),
                      ^(int error){
                         // Cleanup code for normal channel operation.
                         // Assumes that dispatch_io_close was called elsewhere.
                         if (error == 0) {
                            dispatch_release(self.channel);
                            self.channel = NULL;
                         }
                      });
}

使用 DispatchIO，init 需要一个文件描述符。如何获取文件描述符？

public mutating func openChannelWithURL(anURL: URL) {
    let filePath: String = anURL.path
    DispatchIO.init(type: .stream, fileDescriptor: ?, queue: DispatchQueue.global()) { code in
        print("code: \(code)")
    }
}

我正在尝试以只写模式打开文件，该模式会异步将数据附加到文件。

Answer 1

您没有文件描述符。你有一个文件路径。你调用了错误的初始值设定项。你想要这个：

https://developer.apple.com/documentation/dispatch/dispatchio/2892309-init

如何使用 Swift 获取 DispatchIO 的文件描述符？

How to get the file descriptor for DispatchIO using Swift?

file

grand-central-dispatch

swift