Usage: UNSHIFT <variable name> <word>
  This command prepends the given word to the given variable, padded with
  a space.  Note that the variable may NOT contain the leading "$";
  the command uses the variable name itself, not the expanded contents.
  If the variable does not exist, it is created containing the specified
  word (just as if it were ASSIGNed).

  UNSHIFT is functionally equivalent to the $unshift() function.

See Also:
  ALIAS functions
