Is there any way to add, remove, or modify user accounts via the command line? I'm not talking about an account for a system process or daemon, I mean is there any way to add a user account, change, user real names, icons, FileVault protection, Admin/normal/limited user status, and basically do everything else that can be done in the System Preferences Users preference pane, but via some command line utility?
To create an account in the Users folder
dscl / -create /Users/addfromcli
Create and set the shell property to bash.
dscl / -create /Users/addfromcli UserShell /bin/bash
Create and set the user’s full name. (Displayed in some of the panels/login screen)
dscl / -create /Users/addfromcli RealName "Added From Cli"
Create and set the user’s ID. (this is the unique id, you need to find out what id your last user create was and add one)
dscl / -create /Users/addfromcli UniqueID 503
Create and set the user’s group ID property. (This can be your default group)
dscl / -create /Users/addfromcli PrimaryGroupID 1000
Create and set the user home directory.
dscl / -create /Users/addfromcli NFSHomeDirectory /Local/Users/addfromcli
Set the password. (dont use password as a password)
dscl / -passwd /Users/addfromcli PASSWORD
Some more details can be found on OS X Daily