crange --
return a range of characters from string
Syntax
crangestring firstExpr lastExpr
Description
Returns a range of characters from string
starting at the character indexed by the expression
firstExpr (zero-based) up to the character
indexed by the expression lastExpr.
If the expression firstExpr or lastExpr
starts with the string ``end'', then ``end'' is
replaced with the index of the last character in the
string. If the expression starts with ``len'', then
``len'' is replaced with the length of the string.