运行 在 Objective c 上执行 shell 命令并同时获得输出

Run a shell command on Objective c and simultaneously get output

假设我想通过 Objective C 应用 运行 curl -o http://example.com/file.zip 并且我想要一个包含下载状态的标签或文本框,当命令为 运行宁。也许这可以使用 dispatch_async 来实现,但现在确定如何实现。在标记为重复之前,我找到的方法,运行 命令,以及 after 它已经完成你得到输出。我想在 运行ning 时获得输出,有点像终端仿真器。

您需要使用 standardOutput 属性 将 NSPipe 连接到 NSTask 并注册以接收 可用数据通知。

@interface TaskMonitor: NSObject
@property NSPipe *outputPipe;
@end

@implementation TaskMonitor

-(void)captureStandardOutput:(NSTask *)process {

  self.outputPipe = [NSPipe new];
  process.standardOutput = self.outputPipe;

  //listen for data available
  [self.outputPipe.fileHandleForReading waitForDataInBackgroundAndNotify];

  [[NSNotificationCenter defaultCenter] addObserverForName:NSFileHandleDataAvailableNotification object:self.outputPipe.fileHandleForReading queue:nil usingBlock:^(NSNotification * _Nonnull note) {

    NSData *output = self.outputPipe.fileHandleForReading.availableData;
    NSString *outputString = [[NSString alloc] initWithData:output encoding:NSUTF8StringEncoding];

    dispatch_async(dispatch_get_main_queue(), ^{
      // do something with the string chunk that has been received
      NSLog(@"-> %@",outputString);
    });

    //listen again...
    [self.outputPipe.fileHandleForReading waitForDataInBackgroundAndNotify];

  }];

}

@end