[GRASS-user] Error when running a very long command- in Py Scripts

Hi
I know that this may sound a bit weird question but, I have built a script that requires users to insert paths to Landsat images. The thing is, that script commands may became very long, and , I realized just now that, if I try to run through GUI script command is in 2 lines so the second line is not read by parser. Is this normal? How can I avoid this?
Thanks
Kim