How to run minecraft with username/password

[memcallen]

How do you run minecraft with your username and password. I tried going into the run arguments and adding the username and password flags(with my username/password) but I get and error saying could not create java virtual machine. Any help?

 

EDIT:also are .lang files still a thing?(and where can I find out how to use them)

 

EDIT 2:Figured out what I was doing wrong with the .lang file- I forgot to put it in the correct path

[shadowfacts]

My guess is that you added them as VM arguments not program arguments. VM arguments will be passed to the JVM when it starts and if the JVM receives an argument that is invalid, it won't create the instance of the JVM and will give you message somewhere along the lines of what you got. The program arguments are the arguments passed to the program, in this case, Minecraft, you want --username and --password to be program arguments so they get passed to MC and used to login to your account.

[memcallen]

Thanks