OSSP var is a flexible, full-featured, and fast variable construct expansion library. It supports a configurable variable construct syntax very similar to the style found in many scripting languages (like @name, ${name}, $(name), etc.) and provides both simple scalar (${name}) and array (${name[index]}) expansion, plus optionally one or more post-operations on the expanded value (${name:op:op...}). The supported post-operations are length determination, case conversion, defaults, postive and negative alternatives, sub-strings, regular expression-based substitutions, character translations, and padding. Additionally, a meta-construct plus arithmetic expressions for index and range calculations allow (even nested) iterations over array variable expansions (..[..${name[#+1]}..]..). The actual variable value lookup is performed through a callback function, so OSSP var can expand arbitrary values.
