osx - How to run launchd agent/daemon from a NSApplication? -

in nsapplication i've button. when click it, want launch/start daemon/agent. how can proceed? i've tried:

- (void) runagent {     nstask *task = [[nstask alloc] init];     task.launchpath = @"launchctl load /system/library/launchagents/com.mycompany.myagent.plist";     [task setlaunchpath:@"/bin/sh"];     [task launch]; } 

with no success...

    nstask *task = [[nstask alloc] init];     [task setlaunchpath:@"/bin/launchctl"];     [task setarguments:[nsarray arraywithobjects:@"load",@"/system/library/launchagents/com.mycompany.myagent.plist", nil]];     [task launch];