grunt exec with callback

Highlighting grunt exec with callback. Another one for grunt geeks only... so no apologies for source code only approach.

    exec: {            
        //get IP & Set a local variable
        get_ip: {
            command: 'ifconfig | grep -m 1 "inet addr:192.168.1" | cut -c21-31',
            callback: function (error, stdout, stderr) {
                if (error !== null) {
                    grunt.log.error('exec error: ' + error);
                };
                globalConfig.myIP = stdout;
                console.log('set myIP:', globalConfig.myIP);
            },
            stdout: false,
            stderr: false            
        }
    }