Cocoa/ Objective-C Shell Command Line Execution

Question

This is probably a stupid question, but how can I execute a shell command from my Cocoa app?

I have the command as a string "command", but can easily manipulate data as needed.

There is no need to get a returned output value.

Answer 1

NSTask

Using the NSTask class, your program can run another program as a subprocess and can monitor that program’s execution.

Answer 2

If you just want to run something and don't care about the output or return code (for example, you want to touch a file), you can just do

system("touch myfile.txt");

Easy as that.

Answer 3

NSTask is pretty easy to do this with. For a synchronous call, you can use something like this fragment:

NSString *path = @"/path/to/executable";
NSArray *args = [NSArray arrayWithObjects:..., nil];
[[NSTask launchedTaskWithLaunchPath:path arguments:args] waitUntilExit];

The -waitUntilExit call makes sure it finishes before proceeding. If the task can be asynchronous, you can remove that call and just let the NSTask do it's thing.

Answer 4

also see this question:

http://stackoverflow.com/questions/412562/execute-a-terminal-command-from-a-cocoa-app/696942#696942

Answer 5

Any ideas how to do it on iPhone FW 3.0 and above? The 'system' and 'exec...' commands are ignored and NSTask.h header is missing. :(