There are 2 ways SSSU commands can be run from within a file (usually needed in a script).
Login to sssu manually from command line, select the array and run the file containing commands as below (assuming command_file is in working directory):
Login through file and run commands from within the file
select manager SERVER1 username=Administrator password=password1
set options on_error=exit_on_error
select system EVARRAY1
add snapshot snap-vdisk1 vdisk=”\Virtual Disks\vdisk1\ACTIVE” allocation_policy=demand