Running a terminal command from NSButton click

Question

I'm trying to build a basic Mac OS Application using Xcode which allows the user to force eject a CD that gets stuck in their drive without having to reboot their computer each time. Basically I want to have an NSButton on my window labeled "Eject" and I'm looking for the button to execute the Terminal command "drutil tray eject" to forcefully eject the CD from the drive when not responding. I'm kinda a newbie to Xcode and this is my first Mac App.

Thank you! :-)

Answer 1

Use NSTask. Have a look at documentation and Quartz Composer CommandLineTool.

+ (void) executeShellCommandAsynchronously:(NSString*)command
{
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    NSTask *task = [[[NSTask alloc] init] autorelease];
    [task setLaunchPath: @"/bin/sh"]; //we are launching sh, it is wha will process command for us
    [task setStandardInput:[NSFileHandle fileHandleWithNullDevice]]; //stdin is directed to /dev/null
    NSArray *args = [NSArray arrayWithObjects:  @"-c", //-c tells sh to execute commands from the next argument
                     command, //sh will read and execute the commands in this string.
                     nil];
    [task setArguments: args];
    [task launch];
    [command release];
    [pool release];
    return;
}