Question

I am trying to build a Gui for homebrew on mac , with objective-c, but when i try to see the installed packages with the following code it return empty but if i try other command like update it gives me the result, I tried the same with java and the same error occurs.

Git page: feel free to help the project, the code might have a lot of errors I am new to objective-c.

NSTask *task;
task=[[NSTask alloc]init];
[task setLaunchPath:@"/Users/rogeriop062/homebrew/bin/brew"];

NSArray *arguments;
arguments = [NSArray arrayWithObjects:@"list",nil];
[task setArguments: arguments];

NSPipe *pipe;
pipe =[NSPipe pipe];
[task setStandardOutput:pipe];


NSFileHandle *file;
file=[pipe fileHandleForReading];

[task launch];


NSMutableData *data=[NSMutableData dataWithCapacity:1000];

while ([task isRunning]) {

    [data appendData:[file readDataToEndOfFile]];
}
[data appendData:[file readDataToEndOfFile]];


NSString *string;
string =[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"result: %@\n",string);

Answer 1

That’s an interesting project; good for you! Homebrew works very nicely on my Mac. I can’t see anything wrong with your code. I pasted your code into a test routine on my iMac and it worked perfectly. It listed the programs that I had installed with brew. One per line, which I didn’t expect, but it worked. Sorry.

You could also try this. Delete everything in your method from[task launch] to the end, and replace it with this:

task.terminationHandler = ^(NSTask *blockTask) {
    NSMutableData *data=[NSMutableData dataWithCapacity:1000];
    [data appendData:[file readDataToEndOfFile]];
    NSString * string =[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
    NSLog(@"result: %@\n",string);
};
[task launch];

and that produces the same results as your code on my machine – it works, I’m afraid – but it will not take compute time waiting for the result.