Saving System Profiler info in a .spx file using NSTask

Question

In Cocoa, I am trying to implement a button, which when the user clicks on will capture the System profiler report and paste it on the Desktop.

Code

 NSTask *taskDebug;
NSPipe *pipeDebug;
 taskDebug = [[NSTask alloc] init];
[[NSNotificationCenter defaultCenter] addObserver:selfselector:@selector(taskFinished:)       name:NSTaskDidTerminateNotification object:taskDebug];
 [profilerButton setTitle:@"Please Wait"];
 [profilerButton setEnabled:NO];

  [taskDebug setLaunchPath: @"/usr/sbin/system_profiler"];

  NSArray *args = [NSArray arrayWithObjects:@"-xml",@"-detailLevel",@"full",@">", @" 
    ~/Desktop/Profiler.spx",nil];
  [taskDebug setArguments:args];


  [taskDebug launch];

But this does not save the file to the Desktop. Having NSArray *args = [NSArray arrayWithObjects:@"-xml",@"-detailLevel",@"full",nil] works and it drops the whole sys profiler output in the Console Window.

Any tips on why this does not work or how to better implement this ? I am trying to refrain from using a shell script or APpleScript to get the system profiler. If nothing work's that would be my final option. Thanks in advance.

Answer 1

Create an NSPipe, send [taskDebug setStandardOutput: myPipe] and read from the pipe's file handle.

Answer 2

NSArray *args = [NSArray arrayWithObjects:@"-xml",@"-detailLevel",@"full",@">", @"~/Desktop/Profiler.spx",nil];

That won't work because you aren't going through the shell, and > is a shell operator. (Also, ~ isn't special except when you expand it using stringByExpandingTildeInPath.)

Create an NSFileHandle for writing to that Profiler.spx file, making sure to use the full absolute path, not the tilde-abbreviated path. Then, set that NSFileHandle as the task's standard output. This is essentially what the shell does when you use a > operator in it.

Answer 3

This got it done ( thanks to Peter and Costique)

[taskDebug setLaunchPath: @"/usr/sbin/system_profiler"];    
NSArray *args = [NSArray arrayWithObjects:@"-xml",@"-         detailLevel",@"full",nil];


[taskDebug setArguments:args];

[[NSFileManager defaultManager] createFileAtPath: [pathToFile stringByExpandingTildeInPath] contents: nil attributes: nil];

outFile = [ NSFileHandle fileHandleForWritingAtPath:[pathToFile stringByExpandingTildeInPath]];

[taskDebug setStandardOutput:outFile];
[taskDebug launch];