execute lame with NSTask but No Output

Question

I'm new to Objective-C. Currently I'm trying to execute lame with NSTask. The following code seems to be working because Xcode's output space shows me lame's standardoutput i.e. shows same as lame's output on Terminal.

But I can't get any output file i.e. test.mp3 on my desktop. Why I can't get any output? Is there any wrong with my code?

NSTask *task = [[NSTask alloc] init];
[task setLaunchPath:@"/usr/local/bin/lame"];
[task setArguments:[NSArray arrayWithObjects:@"/Users/xanadu62/Music/test.wav",nil]];
[task setStandardOutput:[NSFileHandle fileHandleForWritingAtPath:@"/Users/xanadu62/Desktop/test.mp3"]];
[task launch];

Also, I'd like to use "--preset extreme" as lame option. But "task setArguments:" doesn't allow to use this option as argument. I'd like to know how can I solve this issue too.

Answer 1

Try it this way:

NSTask *task = [[NSTask alloc] init];

[task setLaunchPath:@"/usr/local/bin/lame"];

[task setArguments: [NSArray arrayWithObjects:
                                    @"--preset",
                                    @"extreme",
                                    @"/Users/xanadu62/Music/test.wav",
                                    @"/Users/xanadu62/Desktop/test.mp3", 
                                    nil]
];

[task launch];

You don't need to use pipes.

usage: lame [options] <infile> [outfile]

    <infile> and/or <outfile> can be "-", which means stdin/stdout.