NSTask real-time monitoring output

Question

I can't seem to be able to monitor the output of my NSTask command. To my understanding, NSNotificationCenter must be used. The terminal command I am attempting to run downloads a file from my secured server using various encryption methods (it would be a major pain to rewrite this in objective-c). I am going to need to monitor the result so I can receive the percentage of the completed download.

Here is what I have so far

NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];

task = [[NSTask alloc]  init];
pipe = [[NSPipe alloc] init];

NSDictionary *defaultEnvironment = [[NSProcessInfo processInfo] environment];
NSMutableDictionary *environment = [[NSMutableDictionary alloc] initWithDictionary:defaultEnvironment];
[environment setObject:@"YES" forKey:@"NSUnbufferedIO"];
[task setEnvironment:environment];

[task setLaunchPath:[[NSBundle mainBundle] pathForResource:@"servDecryptor" ofType:nil]];
[task setArguments:[NSArray arrayWithArray:arguments]];
[task setStandardOutput:pipe];

fh = [pipe fileHandleForReading];

[nc addObserver:self
       selector:@selector(ready:)
           name:NSFileHandleReadCompletionNotification
         object:fh];
[nc addObserver:self
       selector:@selector(decFinished:)
           name:NSTaskDidTerminateNotification
         object:task];

[task launch];

[fh readInBackgroundAndNotify];

and

    //Ready method
    [[pipe fileHandleForReading] readInBackgroundAndNotify];
NSData *d;
d = [[note userInfo] valueForKey:NSFileHandleNotificationDataItem];

if ([d length] > 0) {
    NSString *s = [[NSString alloc] initWithData:d          encoding:NSUTF8StringEncoding];

}

Please note: the download starts and progresses without stepping into my second method. However, the application crashes after the download has completed and the process has ended.

score 2 · Accepted Answer · answered Sep 21 '12 at 06:53

-(void)uploadData
{
setenv([@"PASSWORD" UTF8String], [mPassword UTF8String], 1);
[task setLaunchPath:executablePathRoot];
[task setArguments:array];
NSPipe *pipe = [NSPipe pipe];
NSPipe *errorPipe = [NSPipe pipe];
[task setStandardOutput:pipe];
[task setStandardError:errorPipe];
//keeps your log where it belongs
//[task setStandardInput:[NSPipe pipe]];

NSFileHandle *outFile = [pipe fileHandleForReading];
NSFileHandle *errFile = [errorPipe fileHandleForReading];


[task launch];
[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(terminated:)
                                             name:NSTaskDidTerminateNotification
                                           object:task];

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(outData:)
                                             name:NSFileHandleDataAvailableNotification
                                           object:outFile];

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(errData:)
                                             name:NSFileHandleDataAvailableNotification
                                           object:errFile];


[outFile waitForDataInBackgroundAndNotify];
[errFile waitForDataInBackgroundAndNotify];
NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
while(!terminated) 
{
    if (![[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]]) 
    {
        break;
    }
    [pool release];
    pool = [[NSAutoreleasePool alloc] init];
}
[pool release];

[self appendDataFrom:outFile to:output];
[self appendDataFrom:errFile to:error];
//[task waitUntilExit];
[task release];
}


-(void) outData: (NSNotification *) notification
{
NSLog(@"outData");
NSFileHandle *fileHandle = (NSFileHandle*) [notification object];
[self appendDataFrom:fileHandle to:output];
[fileHandle waitForDataInBackgroundAndNotify]; //Checks to see if data is available in a background thread.
}


-(void) errData: (NSNotification *) notification
{
NSLog(@"errData");
NSFileHandle *fileHandle = (NSFileHandle*) [notification object];
[self appendDataFrom:fileHandle to:output];
[fileHandle waitForDataInBackgroundAndNotify];
}

- (void) terminated: (NSNotification *)notification
{
NSLog(@"Task terminated");
[[NSNotificationCenter defaultCenter] removeObserver:self];
terminated =YES;
}

NSTask real-time monitoring output

1 Answers1