我正在使用NSTask以交互方式运行cli应用程序。我用它来通过USB连接提取数据。
我正在使用轮廓和错误管道打开NSTask,但是当我发出命令时,它可以工作,但是在循环中旋转沙滩球,从输出中提取数据。
我希望能够将执行help命令的-(IBAction)clicked:(id)sender按钮混搭,并返回输出:
NSTask *usbCommandTask;
NSPipe *outPipe;
NSPipe *inPipe;
NSPipe *errorPipe;
NSFileHandle *inFile;
NSFileHandle *outFile;
NSTimer *pollTimer;
dispatch_queue_t mtpTask;
@implementation AppDelegate
- (void)commandNotification:(NSNotification *)notification
{
NSData *data = nil;
while ((data = [outFile availableData]) && [data length]){
NSString *myString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"Data: %@",myString);
}
NSLog(@"Execution never gets here");
}
-(void)checkTask
{
if(usbCommandTask){
if([usbCommandTask isRunning])NSLog(@"Task running"); else NSLog(@"Task dead");
} else NSLog(@"Task is nil");
}
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
usbCommandTask = [[NSTask alloc] init];
[usbCommandTask setLaunchPath:@"/Applications/usb-debugger-cli"];
[usbCommandTask setCurrentDirectoryPath:@"/"];
[usbCommandTask setArguments:[NSArray arrayWithObject:@"-i"]];
inPipe = [NSPipe pipe];
[usbCommandTask setStandardInput:inPipe];
outPipe = [NSPipe pipe];
[usbCommandTask setStandardOutput:outPipe];
errorPipe = [NSPipe pipe];
[usbCommandTask setStandardError:errorPipe];
outFile = [outPipe fileHandleForReading];
inFile = [inPipe fileHandleForWriting];
[outFile waitForDataInBackgroundAndNotify];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(commandNotification:)
name:NSFileHandleDataAvailableNotification
object:nil];
pollTimer=[NSTimer scheduledTimerWithTimeInterval:1.0f target:self selector:@selector(checkTask) userInfo:nil repeats:TRUE];
[usbCommandTask launch];
NSLog(@"Launched");
}
- (void)applicationWillTerminate:(NSNotification *)aNotification {
// Insert code here to tear down your application
if(usbCommandTask)[usbCommandTask terminate];
}
- (IBAction)clicked:(id)sender {
if(usbCommandTask){
NSString *command=@"help\n";
NSData *commandData=[NSData dataWithBytes:command.UTF8String length:command.length];
[inFile writeData:commandData];
}
else
{NSLog(@"Comamnd task dead");
}
}
最佳答案
[outFile availableData]
实际上是一个阻塞调用,没有数据或显式EOF,因此它将始终阻塞,而我使用了:
data = [outFile availableData];
NSString *myString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"Data: %@",myString);
[outFile waitForDataInBackgroundAndNotify];
关于cocoa - 使用NSTask交互式访问命令,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/42772624/