# Functions
CheckErr prints a user-friendly error to STDERR and exits with a non-zero exit code.
DefaultSubCommandRun prints a command's help string to the specified output if no arguments (sub-commands) are provided, or a usage error otherwise.
No description provided by the author
RequireNoArguments exits with a usage error if extra arguments are provided.
No description provided by the author
# Variables
ErrExit may be passed to CheckError to instruct it to output nothing but exit with status code 1.